Maria Graças de Luna

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Abstract –This paper proposes the Predictive Direct Power Control (P-DPC), a new control approach where the wellknown direct power control (DPC) is combined with a predictive selection of a voltage-vectors sequence, obtaining both high transient dynamic and constant switching frequency. Two different P-DPC versions are developed based on two different types(More)
This paper presents a novel strategy, optimized by genetic algorithms, to control stand-alone hybrid renewable electrical systems with hydrogen storage. The strategy optimizes the control of the hybrid system minimizing the total cost throughout its lifetime. The optimized hybrid system can be composed of renewable sources (wind, PV and hydro), batteries,(More)
The paper presents a model for motion generation of differential-drive mobile robots. The parameters of the dynamic model allow adjusting the robot translational and rotational behaviours separately. The model takes into account the robot kinematic and dynamic constraints, making the velocities and accelerations bounded and compatible with those the robot(More)
This paper addresses the computation of the steady state behaviour of a subclass of continuous Petri nets under infinite servers semantics. For this class, the visit ratio is fixed by the net structure and the rates associated to the transitions. The class generalises well known net subclasses, as marked graphs or equal conflict net systems. A programming(More)
In order to classify resources, digital libraries have traditionally used different types of lexical ontologies, which describe the terminology used in an area of knowledge. This paper analyzes how lexical ontologies covering different areas of knowledge can be merged to generate an enriched urban terminology. This work proposes a method to combine these(More)
The level-furrow irrigation system consists of furrowing a level-basin. In level-furrows, irrigation proceeds just like in level-basins: the field is flooded from one point and water spreads to irrigate each furrow. Several authors have reported that this irrigation system has a potential to conserve water as compared to level-basin irrigation. However, no(More)
  • Monica Hernandeza, Rosario Barrenab, Gabriel Hernandezb, Guillermo Sapiroc, Alejandro F. Frangia, Maria Graças de Luna
  • 2003
Knowledge of brain aneurysm dimensions is essential during the planning stage of minimally invasive surgical interventions using Guglielmi Detachable Coils (GDC). These parameters are obtained in clinical routine using 2D Maximum Intensity Projection images from Computed Tomographic Angiography (CTA). Automated quantification of the three dimensional(More)
The creation and rendering of realistic water scenes is one of the challenging tasks in Computer Graphics. To reproduce the illumination and colour inside water bodies an algorithm capable of dealing with media with anisotropic and multiple scattering has to be used. We have developed a simulation system based in the discrete ordinates method to solve the(More)
The in vitro susceptibility of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium africanum, Mycobacterium avium, Mycobacterium fortuitum, and Mycobacterium chelonae (M. chelonei) to ticarcillin in combination with calvulanic acid (CA) was studied by the agar dilution method. All the M. tuberculosis, M. bovis, and M. africanum strains were(More)
Aiming to reach a desired final state from a given initial one, this paper addresses the minimum-time decentralized control of Choice-Free continuous Petri nets. It is assumed that the original system is cut into disconnected subsystems by a set of places (buffers). Local control laws are first computed independently in subsystems, based on which the(More)