Abstract

Abstract
In the last decades propofol became established as an intravenous agent for the induction and maintenance of both sedation and general anesthesia procedures. In order to achieve the desired clinical effects appropriate infusion rate strategies must be designed. Moreover, it is important to avoid or minimize associated side effects namely adverse cardiorespiratory effects and delayed recovery. Nowadays, to attain these purposes the continuous propofol delivery is usually performed through target-controlled infusion (TCI) systems whose algorithms rely on pharmacokinetic and pharmacodynamic models. This work presents statistical models to estimate both the infusion rate and the bolus administration. The modeling strategy relies on multivariate linear models, based on patient characteristics such as age, height, weight and gender along with the desired target concentration. A clinical database collected with a RugLoopII device on 84 patients undergoing ultrasonographic endoscopy under sedation-analgesia with propofol and remifentanil is used to estimate the models (training set with 74 cases) and assess their performance (test set with 10 cases). The results obtained in the test set comprising a broad range of characteristics are satisfactory since the models are able to predict bolus, infusion rates and the effect-site concentrations comparable to those of TCI. Furthermore, comparisons of the effect-site concentrations for dosages predicted by the proposed Linear model and the Marsh model for the same target concentration is achieved using Schnider model and a factorial design on the factors (patients characteristics). The results indicate that the Linear model predicts a dosage profile that is faster in leading to an effect-site concentration closer to the desired target concentration.

Abstract
The utility of computer-based teaching-learning systems is generally accepted but several relevant issues remain unsolved in the design of those systems, namely, how to adapt to a learner's specific needs; how to plan corrective feedback; how to fit teaching-learning-assessment techniques to a specific educational context; how to choose the educational tools more appropriate to a teaching-learning-assessment method; how to choose a language to express a pedagogical model; how to adequate the teaching-learning-assessment activities deployment to a specific educational format (distance, face-to-face or blending learning). The aim of this paper is threefold: first, it surveys the most relevant computer-based teaching-learning systems since 1960. Second, it describes the learning design paradigm supported by specific modelling languages. Finally, it presents some reflections on educational material design, more specifically teaching-learning activities, that should be considered by teachers. Those considerations aim at bridging the gap between relevant theoretical aspects and the teachers' daily activities in the design of teaching-learning scenarios.

Abstract
The Ibero-American Network of Distributed Generation and Intelligent Electrical Microgrids is a thematic network of the CYTED programme that performs cooperation activities between leading companies and research groups of the Ibero-American countries in the renewable energy area. This paper presents the results and conclusions of a study carried out recently by the network, which focused on the state of penetration of the distributed generation and the electrical microgrids in the Ibero-American countries that collaborate with the network. A list of these countries, together with the contact details of the main researchers, can be found in Apendix I. © 2014 IEEE.

Abstract

Abstract
Energy storage in low voltage grid is receiving increased attention due to renewables integration and consumption growth, challenges faced nowadays by grid operators. In this work, a study of main implementation issues for community energy storage (CES) is presented along with a comparison between possible solutions for the bidirectional isolated power conversion system (PCS) to interface a battery pack with the electric power grid. The aim of this research is to increase the power density of the power converter and keeping simultaneously the same reliability of traditional solutions. These goals are pursued to be achieved through the reduction of the conversion stages and utilization of new optimization methodologies to reduce the volume of the passive components. The proposed topology for the PCS is based on a matrix converter (MC) that performs a direct AC to AC conversion between the grid and a high-frequency transformer (HFT). With this solution it is possible to eliminate the traditional DC-link capacitor and obtain a single-stage power conversion with bidirectional power flow capability. This proposed solution is evaluated and compared with a conventional two-stage topology through extensive simulation. Two prototypes systems were designed for a 10kW PCS to connect the three-phase 230/400Vrms, 50Hz mains to a battery pack with voltage range of 320V to 490V. Simulation results are presented to assess the power quality provided by the front-end and the battery side converters, as well as performance evaluation and efficiency analysis.