Abstract

Abstract

Abstract
In this paper it was studied the performance evaluation of Doubly-Fed Induction Generator (DFIG) in the analysis of dynamic voltage stability during Low Voltage Ride Through (LVRT) in electric power systems. Two models of wind turbines were analyzed. In one of the models the wind turbines are equipped with pitch control coupled with a Fixed Speed Induction Generator (FSIG) and a shunt capacitor bank. In the other model the wind turbines are equipped with DFIG, crowbar and chopper. To protect the rotor side converter from tripping due to overcurrents in the rotor circuit or overvoltage in the DC link during voltage dips a crowbar was installed in DFIG. Nowadays the most efficient plants use technologies that allow them to stay connected during a fault and to produce again normally after the disturbance The model used can take into account these new technologies. The automatic voltage regulators of the generating units, and the turbine speed governors were modelled in detail. Different load models were used and the under load tap changers were also taken into account. The simulation results were obtained using the EUROSTAG software package. Finally, some conclusions that provide a better understanding of the dynamic voltage stability of a system with FSIG and DFIG models during LVRT are pointed out. © VDE VERLAG GMBH.

Abstract

Abstract
This paper proposes a novel architecture for real-time 3D ball trajectory estimation with a monocular camera in Middle Size League scenario. Our proposed system consists on detecting possible multiple ball candidates in the image, that are filtered in a multi-target data association layer. Validated ball candidates have their 3D trajectory estimated by Maximum Likelihood method (MLM) followed by a recursive refinement obtained with an Extended Kalman Filter (EKF). Our approach was validated in real RoboCup scenario, evaluated recurring to ground truth information obtained by alternative methods allowing overall performance and quality assessment. © 2012 Springer-Verlag Berlin Heidelberg.

Abstract
Ambient Assisted Living environments projects arise as technological responses of the scientific community to problems associated with the population-ageing phenomenon. In theory, these environments should allow de-localization of healthcare services delivery and management to the home, thus containing the economic and social costs associated with old age. The VirtualECare project is one of those environments, enhanced with proactive techniques for a better user experience, focused on elderly chronic patients, through the ability of constant learning and adaption based in user interaction and its contexts. This learning and, consequently, adaption needs, however, unequivocally user identification, especially in multi-user environments. Traditional identification techniques and methodologies are not suitable for these scenario since, usually, require user interaction and wireless identification technique (e.g. RFID, Bluetooth) are very exposed to personification. In order to obtain the expected results we needed a more advanced technology. One possible, appropriate and already fairly developed technique is Facial Recognition. In this paper we present the VirtualECare project approach to Facial Recognition authentication techniques its advantages, disadvantages and possible implementations paths.