Abstract
All over the world, energy companies are investing in technologies to make better use of renewable energy to generate electric power. Wind energy is the renewable energy source that had a higher growing in the last decades and can be considered a hope in future based on dean and sustainable energy. The development of tools that allows operators and maintenance personnel to correlate machinery related information with other operational information such as machine speed, electrical load, and wind speed, are needed.

Abstract
Sailing has been for long times the only means of ship propulsion at sea. Although the performance of a sailing vessel is well below the present power driven ships, either in terms of navigation speed and predictability, wind energy is absolutely renewable, clean and free. Unmanned autonomous sailing boats may exhibit a virtually unlimited autonomy and be able to perform unassisted missions at sea for long periods of time. Promising applications include oceanographic and weather data collecting, surveillance and even military applications. The Microtransat competition, launched in Europe in 2006, has been a key initiative to promote the development of robotic unmanned sailing boats. Various regattas have taken place across Europe and the ultimate challenge will be a transatlantic race. This paper presents an autonomous sailing boat developed at the University of Porto, Portugal, with emphasis on the hardware and software computing infrastructure. This platform is capable of carrying a few kilograms of sensing equipment that can be hooked to the boat's main computer, also providing support for short and long range data communications.

Abstract
In a competitive world such as ours, students must be prepared beforehand to be autonomous, industrious and skilful. Problem-based learning (PBL) is a methodology that can help the students to explore and put to use their own resources, and it can be applied to a wide range of students and subject matters. The project incorporates aspects of electrical engineering and computing skills. This study is dedicated to the learning process to help students to deal with the complexity of an electric power network. This study has conducted a new methodology in educational research by adopting technology for teaching and learning. PBL, as an instructional strategy of active learning, was used and adapted for use in Analysis in Electrical Power Systems programme. This methodology addresses many of the concerns of teachers and professional organizations. Above all, it encourages students to be in charge of their education. It emphasizes critical thinking skills, understanding, learning how to learn, and working cooperatively with others. The benefits of PBL in the Electrical Power Systems course are seen in the way students improved the study and analysis of the security in an electrical power system. This method can also be seen as a benefit for Electric Power Systems where educators strive for improved teaching and learning.

Abstract
Autonomous sailboats are robotic vessels that use wind energy for propulsion and control the sails and rudders without human intervention. The use of autonomous sailboats for ocean sampling has been tentatively proposed before, but there have been minor efforts towards the development and deployment of actual prototypes, due to a number of technical limitations and significant risks of operation. Currently, most of the limitations have been surpassed, with the availability of extremely low power electronics, flexible computational systems, reliable communication devices and high performance renewable power sources. At the same time, some of the major risks have been mitigated, allowing this emerging technology to become an effective tool for a wide range of applications in real scenarios. We illustrate some of these scenarios and we describe the status of the current efforts being made to develop operational prototypes.

Abstract
In this article we describe several methods for the discretization of the differintegral operator s(a), where alpha = u + jv is a complex value. The concept of the conjugated-order differintegral is also introduced, which enables the use of complex-order differintegrals while still producing real-valued time responses and transfer functions. The performance of the resulting approximations is analysed in both the time and frequency domains. Several results are presented that demonstrate its utility in control system design.

Abstract