34 research outputs found
Semi-decentralized Strategies in Structural Vibration Control
In this work, the main ideas involved in the design of overlapping and multi-overlapping controllers via the Inclusion Principle are discussed and illustrated in the context of the Structural Vibration Control of tall buildings under seismic excitation. A detailed theoretical background on the Inclusion Principle and the design of overlapping controllers is provided. Overlapping and multi-overlapping LQR controllers are designed for a simplified five-story building model. Numerical simulations are conducted to asses the performance of the proposed semi-decentralized controllers with positive results
La plaqueta pintada del yacimiento epipaleolÃtico de Picamoixons (Alt Camp, Tarragona) : aproximación al estudio de la cadena operativa
En este trabajo se presenta el estudio realizado sobre una plaqueta pintada localizada en el yacimiento de Picamoixons, cuya cronologÃa oscila entre 9.l70±80 y 11.050±90 B.P. A su vez se desarrolla una metodologÃa referida al medio de aplicación de la pintura mediante las técnicas digital, pincel y "a crayon", en base a un programa experimental. Se describen los primeros resultados y su aplicación a la plaqueta de Picamoixons.In this work we present the study concerning a painted tablet on limestone located at the Picamoixons site, whose dating stands between 9.170±80 and 11.050±90 B.P. At the same time, a methodology is currently being developed regarding the means of application of (he painting through the digital, paintbrush and "a crayon" techniques, based on an experimental programo The frrst results and their application on the Picamoixons tablet are described
LMI-based design of distributed energy-dissipation systems for vibration control of large multi-story structures
In this paper, we present an advanced computational procedure that allows obtaining distributed energy-dissipation systems for large multi-story structures. The proposed methodology is based on a decentralized velocity-feedback energy-to-componentwise-peak (ECWP) controller design approach and can be formulated as a linear matrix inequality (LMI) optimization problem with structure constraints. To demonstrate the effectiveness of the proposed design methodology, a passive damping system is computed for the seismic protection of a 20-story building equipped with a complete set of interstory viscous dampers. The high-performance characteristics of the obtained passive ECWP control system are clearly evidenced by the numerical simulation results. Also, the computational effectiveness of the proposed design procedure is confirmed by the low computation time of the associated LMI optimization problem.Peer ReviewedPostprint (published version
Virtual Ontogeny of Cortical Growth Preceding Mental Illness
Background: Morphology of the human cerebral cortex differs across psychiatric disorders, with neurobiology and developmental origins mostly undetermined. Deviations in the tangential growth of the cerebral cortex during pre/perinatal periods may be reflected in individual variations in cortical surface area later in life. Methods: Interregional profiles of group differences in surface area between cases and controls were generated using T1-weighted magnetic resonance imaging from 27,359 individuals including those with attention-deficit/hyperactivity disorder, autism spectrum disorder, bipolar disorder, major depressive disorder, schizophrenia, and high general psychopathology (through the Child Behavior Checklist). Similarity of interregional profiles of group differences in surface area and prenatal cell-specific gene expression was assessed. Results: Across the 11 cortical regions, group differences in cortical area for attention-deficit/hyperactivity disorder, schizophrenia, and Child Behavior Checklist were dominant in multimodal association cortices. The same interregional profiles were also associated with interregional profiles of (prenatal) gene expression specific to proliferative cells, namely radial glia and intermediate progenitor cells (greater expression, larger difference), as well as differentiated cells, namely excitatory neurons and endothelial and mural cells (greater expression, smaller difference). Finally, these cell types were implicated in known pre/perinatal risk factors for psychosis. Genes coexpressed with radial glia were enriched with genes implicated in congenital abnormalities, birth weight, hypoxia, and starvation. Genes coexpressed with endothelial and mural genes were enriched with genes associated with maternal hypertension and preterm birth. Conclusions: Our findings support a neurodevelopmental model of vulnerability to mental illness whereby prenatal risk factors acting through cell-specific processes lead to deviations from typical brain development during pregnancy
Predicting instrumental mass fractionation (IMF) of stable isotope SIMS analyses by response surface methodology (RSM)
International audienc
Optimal passive-damping design using a decentralized velocity-feedback H-Infinity approach
In this work, a new strategy to design passive energy dissipation systems for vibration control of large structures is presented. The method is based on the equivalence between passive damping systems and fully decentralized static velocity-feedback controllers. This equivalence allows to take advantage of recent developments in static output-feedback control design to formulate the passive-damping design as a single optimization problem with Linear Matrix Inequality constraints. To illustrate the application of the proposed methodology, a passive damping system is designed for the seismic protection of a five-story building with excellent results