2020
Autores
de Araújo, FMA; Fonseca Ferreira, NM; Mascarenhas, VTOC; Adad Filho, JA; Viana Filho, PRF;
Publicação
Lecture Notes in Electrical Engineering
Abstract
In research carried out by the Brazilian Institute of Geography and Statistics (IBGE), alarming data on motor diseases are disclosed, in which it is shown that 7% of the Brazilian population has some type of motor deficiency. The gaming industry is the most profitable entertainment industry today, yet the area of gaming adapted for people with motor disabilities is under-explored. Thinking about it, this work proposes to develop a work environment (Framework) to facilitate the creation of accessible games using eye tracking, thus giving the possibility of playing with just the eyes. © Springer Nature Singapore Pte Ltd 2020.
2020
Autores
Ghahderijani, MM; Camacho, A; Moreira, C; Castilla, M; Garcia de Vicuna, LG;
Publicação
IEEE TRANSACTIONS ON POWER DELIVERY
Abstract
Voltage imbalances are one of the most severe challenges in electrical networks, which negatively affect their loads and other connected equipment. This paper proposes a voltage support control strategy to mitigate the voltage imbalance in inverter-based low voltage distribution networks. The control scheme is derived taking in mind the following control objectives: a) to increase the positive sequence voltage as much as possible, b) to decrease the negative sequence voltage as much as possible, c) to inject the power generated by the primary source, and d) to minimize the output current of the inverter. The innovative contribution of the proposed solution is based on the design of a control algorithm that meets the aforementioned objectives without resorting to communications with other grid components. The theoretical results are experimentally validated by selected tests on a laboratory setup with X/R ratio close to one.
2020
Autores
Afonso, J; Guedes, C; Santos, V; Morais, R; Silva, J; Teixeira, A; Silva, S;
Publicação
FOODS
Abstract
The bioelectrical impedance analysis (BIA) is a non-destructive technique that has been successfully used to assess the body and carcass composition of farm species. This study aimed to predict intramuscular fat (IMF) and physicochemical traits in the longissimus thoracis et lumborum muscle (LM) of beef, using BIA. These traits were evaluated in LM samples of 52 crossbred heifer carcasses. The BIA was performed in LM, using a 50 Hz frequency high precision impedance converter system. A correlation analysis of the studied variables was performed. Then a stepwise with a k-folds cross validation procedure was used to modelling the prediction of IMF and physicochemical traits from BIA parameters (24.5% <= CV <= 47.3%). Wide variation was found for IMF and BIA parameters. In general, correlations of BIA parameters with IMF and physicochemical traits were moderate to high and were similar for all BIA parameters (-0.50 <= r <= 0.50 only for total pigments, a* and pH48). It was possible to predict IMF and physicochemical traits from BIA. The best fit explained 79.3% of the variation in IMF, while for physicochemical traits the best fits were for sarcomere length and shear force (64.4% and 60.5%, respectively). The results confirmed the potential of BIA for objective measurement of meat quality.
2020
Autores
Leite, B; Cardoso, HL; Reis, LP; Soares, C;
Publicação
International Conference on INnovations in Intelligent SysTems and Applications, INISTA 2020, Novi Sad, Serbia, August 24-26, 2020
Abstract
Artificial Intelligence (AI) has seen numerous applications in the area of Education. Through the use of educational technologies such as Intelligent Tutoring Systems (ITS), learning possibilities have increased significantly. One of the main challenges for the widespread use of ITS is the ability to automatically generate questions. Bearing in mind that the act of questioning has been shown to improve the students learning outcomes, Automatic Question Generation (AQG) has proven to be one of the most important applications for optimizing this process. We present a tool for generating factual questions in Portuguese by proposing three distinct approaches. The first one performs a syntax-based analysis of a given text by using the information obtained from Part-of-speech tagging (PoS) and Named Entity Recognition (NER). The second approach carries out a semantic analysis of the sentences, through Semantic Role Labeling (SRL). The last method extracts the inherent dependencies within sentences using Dependency Parsing. All of these methods are possible thanks to Natural Language Processing (NLP) techniques. For evaluation, we have elaborated a pilot test that was answered by Portuguese teachers. The results verify the potential of these different approaches, opening up the possibility to use them in a teaching environment. © 2020 IEEE.
2020
Autores
Sousa, RB; Petry, MR; Moreira, AP;
Publicação
2020 IEEE INTERNATIONAL CONFERENCE ON AUTONOMOUS ROBOT SYSTEMS AND COMPETITIONS (ICARSC 2020)
Abstract
Localisation is a critical problem in ground mobile robots. For dead reckoning, odometry is usually used. A disadvantage of using it alone is unbounded error accumulation. So, odometry calibration is critical in reducing error propagation. This paper presents an analysis of the developments and advances of systematic methods for odometry calibration. Four steering geometries were analysed, namely differential drive, Ackerman, tricycle and omnidirectional. It highlights the advances made on this field and covers the methods since UMBmark was proposed. The points of analysis are the techniques and test paths used, errors considered in calibration, and experiments made to validate each method. It was obtained fifteen methods for differential drive, three for Ackerman, two for tricycle, and three for the omnidirectional steering geometry. A disparity was noted, compared with the real utilisation, between the number of published works addressing differential drive and tricycle/Ackerman. Still, odometry continues evolving since UMBmark was proposed.
2020
Autores
Moreno, P; Areias, M; Rocha, R;
Publicação
Euro-Par 2020: Parallel Processing - 26th International Conference on Parallel and Distributed Computing, Warsaw, Poland, August 24-28, 2020, Proceedings
Abstract
Lock-free implementation techniques are known to improve the overall throughput of concurrent data structures. A hash map is an important data structure used to organize information that must be accessed frequently. A key role of a hash map is the ability to balance workloads by dynamically adjusting its internal data structures in order to provide the fastest possible access to the information. This work extends a previous lock-free hash map design to also support lock-free compression. The main goal is to significantly reduce the depth of the internal hash levels within the hash map, in order to minimize cache misses and increase the overall throughput. To materialize our design, we redesigned the existent search, insert, remove and expand operations in order to maintain the lock-freedom property of the whole design. Experimental results show that lock-free compression effectively improves the search operation and, in doing so, it outperforms the previous design, which was already quite competitive when compared against the concurrent hash map design supported by Intel. © Springer Nature Switzerland AG 2020.
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