Abstract
This paper explores the evolution of productivity of the artisanal dredge fleet that operates in the south coast of Portugal. This fleet is considered to be one of the most significant in the sector, essentially due to the volume and value of its catches. In this context, the study carried out sought in first place to determine variation in productivity over a time window of 10 years (between 1995 and 2004). Secondly, it sought to distinguish the performance of local and coastal vessels comprising the chosen fleet, The performance of the five homeports in the Algarve coast was also compared. We used Malmquist indexes to measure productivity change and explored the impact of changes in stock conditions and in regulatory policies on productivity levels. During the time period analysed, the measures defined by regulatory entities included allowing the use of a new type of dredge and the establishment of fishing quotas per vessel and per species. Finally, the fishing quotas allowed for each vessel were confronted with the captures officially declared.

Abstract
Vehicles rely on the efficiency of dampers to dissipate energy from the motion of vehicle body and wheels, maintaining the vehicle more stable, and improving the contact between tires and the road surface. To achieve an effective monitoring of dampers (or shock absorbers), two different methodologies, capable of assessing, under vehicle normal operation, the condition of the automotive dampers are presented. The proposed methodologies are based in acceleration, temperature and pressure sensing to determine the shock absorber condition, and are therefore suitable for future implementation in low cost fabrication technologies. The results shown that it is possible to have an effective monitoring device, installed in the damper body, capable of continuously determining shock absorber status, and therefore enabling real time diagnosis. Such a diagnosis system can reduce the number of vehicles riding with defective suspension systems and increase the overall vehicle safety.

Abstract
A transition system can be presented either as a binary relation or as a coalgebra for the powerset functor, each representation being obtained from the other by transposition. More generally, a coalgebra for a functor F generalises transition systems in the sense that a shape for transitions is determined by F, typically encoding a signature of methods and observers. This paper explores such a duality to frame in purely relational terms coalgebraic refinement, showing that relational (data) refinement of transition relations, in its two variants, downward and upward (functional) simulations, is equivalent to coalgebraic refinement based on backward and forward morphisms, respectively. Going deeper, it is also shown that downward simulation provides a complete relational rule to prove coalgebraic refinement. With such a single rule the paper defines a pre-ordered calculus for refinement of coalgebras, with bisimilarity as the induced equivalence. The calculus is monotonic with respect to the main relational operators and arbitrary relator F, therefore providing a framework for structural reasoning about refinement.

Abstract
This work presents a system to manage wind turbines maintenance through a predictive model. The system is based on specific maintenance software and hardware for data acquisition and also on algorithms for prediction based on time series. The maintenance software is called SMIT - (Terology Integrated Modular System). The acquisition system can be interconnected with professional, industrial and low cost acquisition systems. The communication channel is based on IP networks, using clock synchronization for data sampling. A time series prediction algorithm runs on low cost hardware, working as a monitoring trigger of the central system.

Abstract
Chick embryos are among the most studied species in development biology because they are easily obtained, highly accessible and present a similar development to that of humans. Normally morphological studies are carried out with confocal microscopy, however in-situ imaging is impossible and in-vivo imaging can only be performed with great difficulty. For confocal microscopy the embryo has to be studied outside the egg, what generally also means a short life expectancy of the embryo. Additionally, extracting the embryo of the egg precludes the possibility of studying its development in its natural environment. In this paper it is shown that en-face optical coherence tomography (en-face OCT) is a possible solution to overcome these difficulties allowing for an in-situ and in-vivo study over a timescale of several days. With en-face OCT it is possible to accompany the development of one single embryo over several days and to acquire high resolution and axially resolved images. © 2009 SPIE-OSA.

Abstract
Lightning caused around 26% of the total number of faults in the Portuguese Transmission system in the analysed period. Based on historical data, this study uses incident data from 2001 until 2008 (2157 faults in overhead lines) and lightning data from 2003 until 2008 (around 1.65 million cloud-to-ground flashes). The performance of the lightning monitoring system is analysed and the statistical analysis of the incidents caused by lightning is made. Therefore, several indicators are presented, such as average failure rate per 100km and the percentage of these faults from the total. In addition, month and hour fault distributions are shown and the overhead lines with the worst performance in terms of lightning are identified. The aim of this analysis is to characterize this type of faults in order to evaluate the impact caused by lightning on an operational level. It will be one of the many inputs of a risk assessment methodology. © 2009 IEEE.