Abstract
Renewable energy sources (RES) are becoming the main players for the sustainability of the planet and achieving a 100% RES energy system has been attested as a good strategy to go forward in many countries. This target however defies the system to integrate highly variable RES in a system that does not allow for shortage on the energy supply. This work presents a possible 100% RES scenario for an electricity system close to the Portuguese estimating and analysing the economic and technical impacts. The sensitivity of the results to aspects related to RES availability, electricity demand, peak load and interconnection capacity for electricity trading were also analysed. The results highlighted the excess of electricity produced in 100% RES systems and the importance of including interconnection capacity to contribute to overcome this problem.

Abstract

Abstract
Today's society is characterized by an abundant growth of data and information within the organizations, largely due to the extrapolation of Information and Communication Technologies (ICT) used to support their daily activities. The growing complexity of IS, has required the appearance of Information Systems Architectures (ISA) for their management and maintenance. The research team has identified relevance in its applicability within the Portuguese Higher Education Institutions (PHE), and a case study with the University of Tras-os-Montes and Alto Douro (UTAD) was drawn. Through the development and implementation of an ISA proposal, UTAD was provided with a transversal view of all the existing IS, allowing validation of the existence/need for IS aimed at managing information and decision-making under a multidimensional perspective, that is, oriented at different organizational levels, from the operational to the strategic level. Given the proposed ISA degree of abstraction, it can be applied to the other institutions within PHE, since they share similar contexts than the one inherent to UTAD.

Abstract

Abstract
Window functions are a sub-class of analytical operators that allow data to be handled in a derived view of a given relation, while taking into account their neighboring tuples. We propose a technique that can be used in the parallel execution of this operator when data is naturally partitioned. The proposed method benefits the cases where the required partitioning is not the natural partitioning employed. Preliminary evaluation shows that we are able to limit data transfer among parallel workers to 14% of the registered transfer when using a naive approach.

Abstract
This paper introduces a logic to support the specification and development of reactive systems on various levels of abstraction, from property specifications, concerning e.g. safety and liveness requirements, to constructive specifications representing concrete processes. This is achieved by combining binders of hybrid logic with regular modalities of dynamic logics in the same formalism, which we call D-down arrow-logic. The semantics of our logic focuses on effective processes and is therefore given in terms of reachable transition systems with initial states. The second part of the paper resorts to this logic to frame stepwise development of reactive systems within the software development methodology proposed by Sannella and Tarlecki. In particular, we instantiate the generic concepts of constructor and abstractor implementations by using standard operators on reactive components, like relabelling and parallel composition, as constructors, and bisimulation for abstraction. We also study vertical composition of implementations which relies on the preservation of bisimularity by the constructions on labeleld transition systems.