Abstract
An artificial neural network concept has been developed for transformer fault diagnosis using dissolved gas-in-oil analysis (DGA). A new methodology for mapping the neural network into a rule-based inference system is described. This mapping makes explicit the knowledge implicitly captured by the neural network during the learning stage, by transforming it into a Fuzzy Inference System. Some studies are reported, illustrating the good results obtained.

Abstract
Mean sea level is a variable of considerable interest in meteorological and oceanographic studies, particularly long-term sea level variation and its relation to climate changes. This study concerns the analysis of monthly mean sea level data from tide gauge stations in the Northeast Atlantic with long and continuous records. Much research effort on mean sea level studies has been focused on identifying long-term linear trends, usually estimated through least-squares fitting of a deterministic function. Here, we estimate nonparametric and robust trends using lowess, a robust smoothing procedure based on locally weighted regression. This approach is more flexible than a linear trend to describe the deterministic part of the variation in tide gauge records, which has a complex structure. A common trend pattern of reduced sea levels around 1975 is found in all the analysed records and interpreted as the result of hydrological and atmospheric forcing associated with drought conditions at the tide gauge sites. This feature is overlooked by a linear regression model. Moreover, nonlinear deterministic behaviour in the time series, such as the one identified, introduces a bias in linear trends determined from short and noisy records.

Abstract
Port Wine ageing process is very important to produce the most appreciated and expensive wines from the class. The process takes decades to accomplish and involves particular techniques which are taken inside refrigerated cellars. Different wines pass through such process to produce 10 year, 20 year, 30 year and 40 year Ports. There are no documented data about color or turbidity evolution during the ageing process. We decided to verify the states of color and spectral turbidity of different aged Gold white port wine. The acquired results show a spectral evolution on transmition and scattered radiation along with color modification which are a close and direct consequence of adopted corrective measures. In measuring the four samples, we have used our spectronephelometer with optical fiber tips to illuminate sample and to acquire transmitted or scattered radiation. Transmition results were calibrated with a standard spectrophotometer at our laboratory, and scattered spectra were measured considering a system calibration with ISO12103 standard dust. We are aware that the four samples were harvested in different years, but the wine type is the same and the ageing process does not differ from one sample to another.

Abstract
In this paper, two approaches, for the estimation of matrices A and C in CV A-type subspace identification algorithms are compared and the differences between the two obtained estimates are analysed. One of the methods, "least squares" based, was proposed in the original CVA algorithm. The other method, inspired in the techniques of the classical Realization Theory and proposed by Verhaegen, is far more efficient. Therefore, although the two methods produce two different estimates, a replacement is proposed and an expression for correction of the estimates is obtained, in order to reduce the loss of accuracy.

Abstract

Abstract
Real time parameter estimation of dynamic models operating in closed loop control is a crucial issue to implement industrial adaptive controllers. Parameter estimation must be seen as one of the key elements to solve a system identification problem, which involves also an experiment design, the selection of a model structure, and the model validation. This paper describes some approaches to compute the transfer function parameters of time-varying systems under closed loop control. To point the limitations and advantages of each method, with focus on robustness and quality of the model estimates, the techniques are applied to compute the parameters of a time varying discrete system, with known structure, under PI- Proportional-Integral control.