Abstract
This paper proposes a new probabilistic model for active low-voltage prosumers suitable for distribution expansion planning studies. The load uncertainty of these consumers is considered through a range of load profiles by segmenting the energy consumption according to the different energy uses. Then, consumption adjustments are simulated using a nonhomogenous Poisson process based on the energy usage preferences and the financial gains according to the tariff scheme. A case study based on the modified IEEE 33-Bus test system with real data collected from a Brazilian distribution company is performed in order to analyze the impact of the load profiles in scenarios with high penetration of renewable distributed generation (DG). The experiments carried out reveal that considerable monetary savings in the expansion of the distribution grid can be achieved for this case study (up to 37%) as compared with the alternative with no active demand (AD) by exploiting the flexibility associated with the active behavior of prosumers as a response to price signals and/or by permitting adequate levels for the integration of DG into the distribution grid.

Abstract
This paper addresses the stability analysis of a real island power system following the transformation occurring in the generation portfolio: from a 100 % synchronous-generation-based system (associated to a fleet of diesel generators) to a hybrid power system dominated by power electronics converters. The integration of a battery-wind-photovoltaic power plant in the island creates the necessary conditions for operating the system without synchronous units scenarios with a system dominated by power electronics - or, at least to minimize its use - scenarios with a reduced number of synchronous units in operation. The possibility of operating the system under these conditions is assured by grid-forming inverters connected to battery energy storage systems, that are responsible for performing frequency and voltage control tasks either in parallel with synchronous units or when synchronous units are disconnected. The resulting transient stability issues for the aforementioned operational scenarios are discussed and evaluated through dynamic simulations.

Abstract
It is undeniable that the world is taking a turn for the digital. Banking, shopping, working, education, entertainment, everything has its own digital equivalent or means thereof. This includes language learning. Nowadays, there is a myriad of (mobile and digital) possibilities to study, learn and improve a person’s knowledge of virtually any language. Thus, there should be potential benefits in their use in academic level (foreign) language learning, but also in an individual “self-learning" process. In this study, we choose to tackle mobile apps and their impact in the teaching/learning of languages, the perception of their usefulness and their impact (positive or otherwise) on the subject. To achieve this, a literature review on the subject was conducted, in addition to twenty interviews performed with students of the University of Aveiro. Supported by our literature review, we can safely state that language learning is just one of the many segments of both life and academia that can only be positively affected by digitalisation, and that we will continue seeing a rising trend towards that goal.

Abstract

Abstract
The decarbonization of the electrical system (ES) is an inevitable truth. Thus, many economies that share concerns about climate change, invest in renewable sources to help contain the global warming. However, the massive integration of these renewable sources, which brings more intermittency and volatility, together with the natural variation of consumption, pose greater challenges that should be mitigated with adequate tools, as offered by a liberalized and organized electrical market. To help cost reduction in a market environment, the coordination between different Transmission System Operators (TSOs) is of utmost importance. The objective of this work is to provide a framework analysis for the sharing of ancillary services (AS) in the context of the Iberian ES, in particular a techno-economic analysis for the secondary reserve (SR) control. The SR control is fundamental to correct load variations and help stabilize the ES where the TSOs are inserted. To this end, the main goal is to control the regional imbalance of the Iberian Peninsula, in a coordinated way, with a minimization of costs. The results show that it is possible to generate synergies in 45% of the market periods and an average profit of 3.4 M(sic) per year. There are enough reasons to implement the coordination procedures between the Iberian TSOs in order to manage their own SRs in a profitable and reliable way, and to become more competitive when exchanging with other European TSOs.

Abstract
This study presents and applies noninvasive subject specific validation of human whole-body (WB) center of mass (COM) kinematic from 3D anthropometric multibody model using dynamic data from ground reaction forces during impulse phase at standard maximum vertical jump (MVJ) with long countermovement (CM) on countermovement jump (CMJ) and short CM on drop jump (DJ) for comparison with MVJ without CM on squat jump (SJ), assessing lower limb CM contribution and muscle stretch-shortening cycle (SSC) at WB COM vertical impulse. A small group of n = 6 sports and physical education degree students with (21.5 ± 1.4) years old, without previous injuries, specific sport abilities or train were weighed (76.7 ± 9.3) kg and their height measured (1.79 ± 0.06) m. Adhesive reflective marks were attached at main upper and lower limb joints. Each subject performed a total of 3 trial at each MVJ, CMJ, DJ and SJ. During trial tests kinematics of anatomical points were registered with two JVC GR-VL9800 digital video cameras at 100 Hz and ground reaction forces with AMTI platform model BP2416-4000 CE operating at 1000 Hz. WB COM kinematics was determined using calibrated SIMI motion tracking of joint reflective marks and Dempster model selecting vertical WB COM displacement ?zk according to higher amplitude and research interest on MVJ WB COM movement for CM and SSC assessment. Dynamic of WB COM vertical displacement ?zd was determined from double time integration of COM vertical acceleration. Comparison of kinematic ?zk and dynamic ?zd was statistically tested on average and variance at each MVJ type, ?zk with ?zd and on root mean square-error (RMSE) during impulse phase. Results present similar variability of ?zk and ?zd at each MVJ p > 0.05, with mean values discriminating CMJ different means p < 0.05 from DJ and SJ with equal means p > 0.05, pointing dynamic data as suitable for validation of WB COM movement from 3D anthropometric image as well as for detection of different RMSE at each type of MVJ, its influence on assessment of CM and SSC and improve accuracy on kinematic, dynamic measurements and models. © Springer Nature Switzerland AG 2019.