Abstract
A technique for the demodulation of fiber Bragg grating (FBG) sensors based on the use of a second wavelength-matched FBG receiver to track wavelength shifts from the FBG sensor is analyzed, particularly regarding its sensitivity as determined by primary noise sources. Numerical and experimental results show that there is an optimum Bragg wavelength difference between the two FBG's that maximizes the sensitivity for this demodulation technique. (C) 1997 Optical Society of America

Abstract
For a greenhouse located at UTAD-University, the methods used to estimate in real-time the parameters of the inside air temperature model will be described. The structure and the parameters of the climate discrete-time dynamic model were previously identified using data acquired during two different periods of the year. Several experiments showed that the second-order models identified achieve a close agreement between simulated and experimental data. Afterwards it has been found that parameters change with varying operational conditions. Thus, for a efficient use of these models in real-time control a recursive identification technique for the estimation of the parameters was implemented.

Abstract
This paper describes the implementation of a distributed data acquisition network based on the 80C592 microcontroller from Intel. Each Station is connected in a hierarchical way to form a tree topology. The lower level network stations, designated by Slaves, are dedicate to the data acquisition and the generation of control signals. The upper level, Masters, are responsible for the communications control. Both networks uses a CAN - Controller Area Network - Bus, for Data Transferring, and the global Network is also connected to a PC, via CAN. A device router, NetManager, was implemented to support total intrinsic requirements at the communication level. This type of connection allows total configuration from a personal computer, PC, in which runs a software application developed for Windows(TM) environments. The tests performed at the laboratory, with transmission rates varying from 40Kbits/s to 1Mbits/s, showed that the communications were performed without errors for cable lengths of 1100m to 40m, respectively. This system is now being installed in a set of environmental chambers and greenhouses located on UTAD, where it will be monitored and controlled the air temperatures and humidities, the CO2 and ammonia concentrations and the radiation level.

Abstract
This paper accompanies the demonstration of CAMILA, an experimental platform for formal software development, rooted in the tradition of constructive specification methods. The CAMILA approach is an attempt to make available at software development level the basic problem solving strategy one got used to from school physics -- create, experiment and reason on a mathematical model. Based on a notion of formal software component, it encompasses a set-theoretic language and an in equational calculus for classification and refinement. Its kernel is a functional prototyping environment, fully connectable to external applications, equipped with a classified component repository and distribution facilities. © Springer-Verlag Berlin Heidelberg 1997.

Abstract
Run-time work distribution in parallel programming systems is usually accomplished through the use of dynamic scheduling heuristics. Their sensitivity to run-time information such as global work-load, task granularity, data dependencies, locality of information, among others, is essential when trying to optimize performance. Adaptive schedulers that base their decisions on feed-back from the system are therefore of special importance. We have developed and used a general purpose parallel programming system, the pSystem, that also served as a test-bed environment on which we have experimented and studied the performance of distinct scheduling heuristics. Currently, we have two versions of the system: one based on Unix processes; and the other on Solaris threads. Threads (particularly user-level threads) are usually associated with low execution overheads, since they require minimal interaction with the operating system kernel This suggests that lower grain parallelism may be more effectively exploited with a thread-based parallel programming system. Performance analysis of both implementations over a Set of well known benchmarks, with various schedulers, shows that threads scale better under higher system loads and/or when the granularity of the tasks being executed is below a given threshold value. This paper starts with a description of the design and implementation of the pSystem computational model, followed by a detailed description of several experiments and the analysis of their results. (C) 1997 John Wiley & Sons, Ltd.

Abstract
This paper addresses source clock recovery in ATM networks for real-time services which require a timing relation between source and destination. A detailed jitter analysis is performed for the synchronous methods, from which a simple design approach is suggested for the clock recovery system. A new timing information transport protocol is proposed for constant bit rate and variable bit rate real-time services, leading to a unified ATM Adaptation Layer for both types of services. The method presented is called Generic Synchronous Technique (GST) and exhibits the following properties: (a) good control on its parameters to satisfy jitter objectives;(b) decoupling between timing and service information; (c) efficient coding leading to reduced overhead; (d) good transmission error immunity and (e) simple implementation. As a case study, it is shown that GST provides adequate clock recovery for MPEG video signals, in the most stringent case when the reconstructed system clock is used to derive a chrominance sub-carrier for use in composite video.