Circuit implementation of piecewise-affine functions based on lattice representation

This paper introduces a digital architecture to implement piecewise-affine (PWA) functions based on representation methods from the lattice theory. Given an explicit and continuous PWA function, the parameters required to implement the lattice approach can be obtained by an off-line preprocessing that can be automated. Other advantages of the proposal are that it implements a continuous PWA function with potentially no errors and the minimum number of parameters to store. This has been proven experimentally by implementing the proposal in a Xilinx FPGA and comparing its performance with other implementations, all of them addressing a typical non linear control problem.Comunidad Europea FP7-IST-248858Ministerio de Ciencia e Innovación TEC2008-04920 y DPI2008-03847Junta de Andalucía P08-TIC-0367

Representation of Bed Stresses within a Model of Chesapeake Bay

This project focused on numerical modeling of the Estuarine Turbidity Maximum (ETM) with the goal of improving the representation of the bottom boundary layer and turbulent mixing within the Chesapeake Bay Program’s model [see Cerco and Noel, 2004]. The effort has been part of the EPA’s sediment modeling initiative for the Chesapeake Bay, in coordination with the U.S. Army Corps of Engineers (USACE), Engineering Research and Development Center (ERDC). Research activities focused on the Upper Chesapeake Bay and major tributaries in Maryland (such as the Potomac River); and assisted management of the U.S. EPA TMDL (Total Maximum Daily Load) project under the provision of the 1972 Clean Water Act. This document reports progress made during the study. Many of the analysis were extended beyond the Upper Chesapeake Bay so that the results included the entire Chesapeake Bay and major tributaries, to assist in ERDC baywide modeling efforts. Figure 1 shows the bathymetry of Chesapeake Bay, and a representative grid used by the ERDC hydrodynamic and water quality model. This effort was divided into three tasks: (1) estimation of bed shear stress, (2) data analysis, and (3) technology transfer. The following lists progress made within each task throughout the three year program

Dispositivi e circuiti elettronici di potenza: modelli e caratterizzazione sperimentale

Simulazioni elettrotermiche di AlGaN/GaN Hemt per la determinazione delle temperature di canale e l'influenza della retroazione termica. Simulazioni a livello fisico e misure in condizioni realistiche di Diodi PiN: caratterizzazione del fenomeno del Breakdown e del reverse recovery in dispositivi veloci. Progettazione di un convertitore di frequenza per altissime potenze