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Publications

2011

State estimation model including synchronized phasor measurements

Authors
Castro Vide, PS; Maciel Barbosa, FP; Ferreira, IM;

Publication
Proceedings of the Universities Power Engineering Conference

Abstract
State estimation plays an important role in real time security monitoring and control of power systems. With increasing implementation of PMUs across the electric power grids and the ability of the Phasor Measurement Unit (PMU) to directly measure the system state, the use of these measurements to improve the precision of state estimator becomes imperative. In this paper, a new state estimator including voltage and current phasors and traditional measurements is proposed. The methodology is validated by simulation results on the 14 and 30 IEEE bus test systems. Several comparisons between the use of SCADA measurements and PMU measurements are exposed. Discussion concerning statistical robustness of the implemented state estimators is presented. © VDE VERLAG GMBH.

2011

A True Power Detector for RF PA Built-In Calibration and Testing

Authors
da Mota, PF; da Silva, JM;

Publication
2011 DESIGN, AUTOMATION & TEST IN EUROPE (DATE)

Abstract
Different built-in self testing schemes for RF circuits have been developed resorting to peak voltage detectors. These are simple to implement but provide a conditional RF power measurement accuracy as impedance is assumed to be known. A true power detector is presented which allows obtaining more accurate measurements, namely as far as output load variations are concerned. The theoretical fundaments underlining the power detector operating principle are presented and simulation and experimental results obtained with a prototype chip are described which confirm the benefits of measuring true power, comparing to output peak voltage, when observing output load matching deviations and complex waveforms.

2011

Customized neural network system for dynamic security preventive control

Authors
Fidalgo, JN;

Publication
International Journal of Power and Energy Systems

Abstract
This paper proposes a new methodology for dynamic security assessment and preventive control. In the first phase, an artificial neural network (ANN) is trained to provide the security status. ANN inputs are settled by a feature selection approach that takes into account the requisites of the control algorithm, to be applied in the second phase. The adaptive control methodology is based on the steepest descent method, where the usual explicit math functions to be dealt with are emulated by the trained ANN. To illustrate the developed approach, the methodology was applied to the control of dynamic security of Madeira island power system. Results attained so far show that the proposed approach was able to find the optimal control actions.

2011

Modeling places for interactive media and entertainment applications

Authors
Rui, N;

Publication
Conference on Human Factors in Computing Systems - Proceedings

Abstract
Taking advantage of the multitude of cameras now available and capable of recording all aspects of our lives, this work explores the notion of virtualizing a physical place using cameras and sharing the resulting model with others. This social sharing would create new forms of relationship and common space discovery that would enhance video chats and virtual visiting of physical places. Furthermore, the research will consider the possible interactive applications, from games to augmented reality, which can take advantage of the created spatial and temporal models.

2011

NUVE: In Between the Analog and Virtual Body

Authors
Moura, JM; Barros, N; Branco, P; Marcos, AF;

Publication
TEI 2011: PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON TANGIBLE EMBEDDED AND EMBODIED INTERACTION

Abstract
NUVE is an artistic project that aims to explore the artistic possibilities offered by the digital dance performances in the interaction between the individual and his virtual double. In NUVE we conceptualized, developed and implemented a digital artifact, resulting in a fluid digital performance based on the theme of the analog body versus the digital virtual body.

2011

Method for the introduction of Creativity in the Information System planning process

Authors
Santos, V; Amaral, L; Mamede, H;

Publication
SISTEMAS E TECNOLOGIAS DE INFORMACAO, VOL I

Abstract

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