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Publicações

Publicações por Fernando Maciel Barbosa

2019

The VirtualSign Channel for the Communication Between Deaf and Hearing Users

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.

2018

Blind/Deaf Comunication API for Assisted Translated Educational Digital Content

Autores
Ulisses, J; Oliveira, T; Rocha, E; Escudeiro, PM; Escudeiro, N; Barbosa, FM;

Publicação
2018 28TH EAEEIE ANNUAL CONFERENCE (EAEEIE)

Abstract
With the rise of usage in digital content in education, deaf and blind communities face communication barriers which as a result makes education less inclusive. These barriers do not allow them to integrate within the larger scholarly communities as most tools used for information dissemination remain inaccessible to them. This paper presents BDC-API (Blind/Deaf Communications API), a free-to-use modular toolkit that will ease accessibility for the blind and deaf communities to digital education content. This content includes the use cases of Massive Online Open Courses and Serious Games used in education. BDC-API incorporates the use of state of the art technologies such as, 3D sign language translator, grammar translation, voice recognition and text-to-speech. This paper demonstrates in greater detail, how these technologies culminate in the creation of an API ready to use for any educational digital content and how the BDC-API can ensure higher quality of digital content.

2013

Metric indices for performance evaluation of a mixed measurement based state estimator

Autores
Vide, PC; Barbosa, FPM; Carvalho, JAB;

Publicação
Advances in Electrical and Electronic Engineering

Abstract
With the development of synchronized phasor measurement technology in recent years, it gains great interest the use of PMU measurements to improve state estimation performances due to their synchronized characteristics and high data transmission speedThe ability of the Phasor Measurement Units (PMU) to directly measure the system state is a key over SCADA measurement system. PMU measurements are superior to the conventional SCADA measurements in terms of resolution and accuracy. Since the majority of measurements in existing estimators are from conventional SCADA measurement system, it is hard to be fully replaced by PMUs in the near future so state estimators including both phasor and conventional SCADA measurements are being consideredIn this paper, a mixed measurement (SCADA and PMU measurements) state estimator is proposedSeveral useful measures for evaluating various aspects of the performance of the mixed measurement state estimator are proposed and explainedState Estimator validity, performance and characteristics of the results on IEEE 14 bus test system and IEEE 30 bus test system are presented. © ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING.

1998

Effect of the generators tripping in the transient stability of an electrical power system using the extended equal area criteria

Autores
Ferreira, CMM; Pinto, JAD; Barbosa, FPM;

Publicação
POWERCON '98: 1998 INTERNATIONAL CONFERENCE ON POWER SYSTEM TECHNOLOGY - PROCEEDINGS, VOLS 1 AND 2

Abstract
In this paper it is studied and analysed the transient stability of a test power network, considering the tripping of one or more generators. It was used the software package TRANsySTEM that the authors developed for transient security assessment of a multimachine power system. These computer programs use the extended equal area criteria formulation. The results obtained with this direct approach were compared with the solutions produced by the Runge-Kutta method. It is also analysed the influence of the sudden increase in the electromagnetic torque in the rotor shaft fatigue life of the remaining generators, when one or more power units are tripped. Finally, some conclusions that provide a valuable contribution to the understanding of the transient security assessment of a multimachine power system are pointed out.

2000

Distributed processing in power system state estimation

Autores
Carvalho, JB; Barbosa, FM;

Publicação
MELECON 2000: INFORMATION TECHNOLOGY AND ELECTROTECHNOLOGY FOR THE MEDITERRANEAN COUNTRIES, VOLS 1-3, PROCEEDINGS

Abstract
The State Estimation is nowadays considered the fundamental element of modern electrical power networks control centers. In this paper we develop a theoretically robust and computationally efficient state estimator algorithm, to solve the WLS problem by using parallel processing, The computational aspects of the parallel processing, was analyzed and tested using the IEEE 14, 57 and 118 bus systems. Computational experiments are compared with standard WLS methods, in the integral and distributed version. An evaluation of the degree of natural decoupling in the state estimation problem is rise performed. The results indicate that a distributed processing for state estimation, is the better way to adopt the parallel computing in power systems energy.

2010

Indicators for Voltage Collapse Margins

Autores
Reis, C; Barbosa, FPM;

Publicação
2010 ASIA-PACIFIC POWER AND ENERGY ENGINEERING CONFERENCE (APPEEC)

Abstract
This paper introduces several different indices in order to characterize the voltage stability of a power system. Voltage instability is a phenomenon which often contributes to the development of power system disturbances. Therefore, is very important to know how a power system is close to voltage collapse. The feasibility of the reported methods is shown by numerical studies in IEEE 57 bus test system. The simulation results are in close agreement.

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