2019
Autores
Oliveira, T; Escudeiro, N; Escudeiro, P; Rocha, E; Barbosa, FM;
Publicação
IEEE REVISTA IBEROAMERICANA DE TECNOLOGIAS DEL APRENDIZAJE-IEEE RITA
Abstract
Deaf students, who use sign language as their mother language, continuously experience difficulties to communicate with non-deaf in their daily lives. This is a severe handicap in education settings seriously jeopardizing deaf people chances to progress in their professional career. Deaf people's comprehension of texts is limited due to grammar differences between sign and oral languages. There is a need to improve the communication between deaf and non-deaf and to support deaf students in environments where they are unable to be accompanied by sign interpreters. This article details the improvements and current structure of the VirtualSign platform, a bidirectional sign language to text translation tool in development since 2015. The platform has two main components, sign to text and text to sign, that are both described. Translation from text to sign relies on a 3D avatar. Translation from sign to text relies on a set of data gloves and Kinect. In this paper we discuss the relevance of different types of data gloves. VirtualSign is being developed in cooperation with the deaf communities from six different European countries and Brazil. This solution to support deaf students in educational settings has received positive feedback on several tests and pilot experiments. Some planned improvements and future functionalities for the tool are also mentioned and detailed.
2019
Autores
Rodrigues, PLS; Jacobina, CB; de Freitas, NB;
Publicação
IET POWER ELECTRONICS
Abstract
This study presents an ac-dc-ac converter with eight controlled switches. The proposed topology is applied as a universal active power filter, compensating for disturbances in the grid voltage, voltage sags/swells, and harmonics generated by non-linear loads. The difference between the proposed and conventional solution is the addition of an uncontrolled leg (composed only of diodes) to increase the number of voltage levels, reducing harmonics and the average switching frequency. For performance comparisons, current total harmonic distortion (THD), voltage weighted THD, switching and conduction losses of the semiconductors, and average switching frequency were used as parameters. Control and pulse-width modulation techniques based on space vector approaches were developed to eliminate zero-crossing distortions caused by the use of the uncontrolled leg. Simulation and experimental results were presented for validation of the mathematical model.
2019
Autores
Liberato, M; Paredes, H; Ramos, A; Reis, A; Hénin, R; Barroso, J;
Publicação
Abstract
2019
Autores
Kurunathan, H; Severino, R; Koubaa, A; Tovar, E;
Publicação
IEEE ACCESS
Abstract
Recent advancements in the IoT domain have been pushing for stronger demands of Quality-of-Service (QoS) and in particular for improved determinism for time-critical wireless communications under power constraints. The IEEE 802.15.4e standard protocol introduced several new MAC behaviors that provide enhanced time-critical and reliable communications. The Deterministic Synchronous Multichannel Extension (DSME) is one of its prominent MAC behaviors that combines contention-based and contention-free communication, guaranteeing bounded delays and improved reliability and scalability by leveraging multi-channel access and CAP reduction. However, DSME has a multi-superframe structure, which is statically defined at the beginning of the network. As the network evolves dynamically by changing its traffic characteristics, these static settings can affect the overall throughput and increase the network delay because of improper allocation of bandwidth. In this paper, we address this problem, and we present a dynamic multi-superframe tuning technique that dynamically adapts the multi-superframe structure based on the size of the network. This technique improves the QoS by providing 15-30% increase in throughput and 15-35% decrease in delay when compared to static DSME networks.
2019
Autores
Faria, BM; Ribeiro, JD; Moreira, AP; Reis, LP;
Publicação
EXPERT SYSTEMS
Abstract
Integration in the world of sport is one way for individuals with disabilities or motor disorders to feel more socially integrated, independent, and confident. Boccia is a Paralympic sport, which is increasingly getting more attention around the world. These facts have contributed to the objectives of this work. Including it in the serious games category enables to develop and rehabilitate the cognitive capabilities. The main focus was BC3 classification athletes (users with limited motor characteristics that require the use of an assistive device-a ramp, in this case). This paper describes a realistic Boccia game simulator adapted for people with disabilities that integrates a set of features that includes real physics and social features. These features can be used to enhance the interest of nonpractitioners of the sport and to improve the training conditions. The official Boccia regulation was added to the design of the simulator. The usability and approximation to the reality of the simulator were tested and validated based on the tests performed and data collected via a survey of users with no motor or psychological disorders. Realism and usability rating was almost excellent, and good results were achieved at the assessment of the game experience.
2019
Autores
Jahromi, HN; Jorge, AM;
Publicação
PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-ENERGY
Abstract
Low oil and gas prices have motivated petroleum executives to look into cost reduction in their supply chains more seriously. To this end, a technology considered in hydrocarbon exploration is data science. There are three exploration-related geoscientific domains in which data science is applied: surface geology, structural geology and reservoir property issues. This research provides an in-depth perspective on data science applications in these domains by considering a variety of work in each of them. The result is an understanding of the specific geoscientific problems studied in the literature along with the relative data science models. This way, this work tries to lay the ground for a mutual understanding on oil and gas exploration between the data scientists and geoscientists.
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