62 research outputs found

    Controller tuning by means of multi-objective optimization algorithms: a global tuning framework

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    © 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A holistic multi-objective optimization design technique for controller tuning is presented. This approach gives control engineers greater flexibility to select a controller that matches their specifications. Furthermore, for a given controller it is simple to analyze the tradeoff achieved between conflicting objectives. By using the multi-objective design technique it is also possible to perform a global comparison between different control strategies in a simple and robust way. This approach thereby enables an analysis to be made of whether a preference for a certain control technique is justified. This proposal is evaluated and validated in a nonlinear multiple-input multiple-output system using two control strategies: a classical proportional- integral-derivative control scheme and a feedback state controller.This work was supported in part by the FPI-2010/19 Grant and the Project PAID-06-11 from the Universitat Politecnica de Valencia and in part by the Projects DPI2008-02133, TIN2011-28082, and ENE2011-25900 from the Spanish Ministry of Science and Innovation.Reynoso Meza, G.; García-Nieto Rodríguez, S.; Sanchís Saez, J.; Blasco, X. (2013). Controller tuning by means of multi-objective optimization algorithms: a global tuning framework. IEEE Transactions on Control Systems Technology. 21(2):445-458. https://doi.org/10.1109/TCST.2012.2185698S44545821

    Modelling, Simulation and Control of a Twin Rotor MIMO-System

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    The object of the project is to simulate and control the laboratory helicopter model called Twin-Rotor Multiple Input-Multiple Output System (TRMS 33-220), manufactured by Feedback Instruments Limited Company. So the first aim was to get familiar with the physical basics of the model what implicated an intensive literature research at the beginning of the work on this project. Having built up the basic mathematical model there was to deal with adjusting the particular parameters by engaging several experiment on the real model comparing the results of the simulation done in Matlab/Simulink. This was one of the most delicate tasks during the projects since there was to deal with constants that were not directly measurable and because particular parts of the model had been changed in the past so that the constant parameters given in the manual went out of date. The control design as well was done using Matlab/Simulink Having reached satisfactory results of the model further experiments were thenceforward on a simulator, firstly implemented in Labview, then embedded on a real-time platform called PXI-1002 manufactured by National Instruments to avoid physical damages of the real model by possible failures during the controller testing. The two control objects were first to keep the helicopter at a certain point and second to follow a given trajectory. So the first effort to create a control was to design two independent PID-Controllers, one for the vertical axis and one for the horizontal one, considering the cross-coupling forces as disturbance. This form of control worked out quite fine as long as only one input was changed. To compensate the disturbances correctly we had to deal with a different type, called state-space-control. The final task was to run the designed controller on the PXI-1002 controlling the physical system.Gabriel Christoph, BX.; García-Nieto Rodríguez, S. (2016). Modelling, Simulation and Control of a Twin Rotor MIMO-System. http://hdl.handle.net/10251/6634

    Multi-Objective Optimization for Wind Estimation and Aircraft Model Identification

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    In this paper, a novel method for aerodynamic model identification of a micro-air vehicle is proposed. The principal contribution is a technique of wind estimation that provides information about the existing wind during flight when no air-data sensors are available. The estimation technique employs multi-objective optimization algorithms that utilize identification errors to propose the wind-speed components that best fit the dynamic behavior observed. Once the wind speed is estimated, the flight experimentation data are corrected and utilized to perform an identification of the aircraft model parameters. A multi-objective optimization algorithm is also used, but with the objective of estimating the aerodynamic stability and control derivatives. Employing data from different flights offers the possibility of obtaining sets of models that form the Pareto fronts. Deciding which model best adjusts to the experiments performed (compromise model) will be the ultimate task of the control engineer.The authors would like to thank the Spanish Ministry of Innovation and Science for providing funding through grant BES-2012-056210 and projects TIN-2011-28082 and ENE-25900. We also want to acknowledge the Generalitat Valenciana for financing this work through project PROMETEO/2012/028.Velasco Carrau, J.; García-Nieto Rodríguez, S.; Salcedo Romero De Ávila, JV.; Bishop, RH. (2015). Multi-Objective Optimization for Wind Estimation and Aircraft Model Identification. Journal of Guidance, Control, and Dynamics. 39(2):372-389. https://doi.org/10.2514/1.G001294S37238939

    Diseño Conceptual Proyecto H200

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    El documento muestra el diseño conceptual previo para el desarrollo de la aeronave no tripulada denominada H200, cuyo principal objetivo es poder embarcar una pila de hidrógeno tipo PEM para extender la autonomía de vuelo.Costea Andronache, SA.; Cerdán Torres, JD.; Such García, JA.; García-Cuevas González, LM.; García-Nieto Rodríguez, S. (2023). Diseño Conceptual Proyecto H200. Universitat Politècnica de València. http://hdl.handle.net/10251/19444

    Role of age and comorbidities in mortality of patients with infective endocarditis

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    [Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

    El derecho del trabajo y de la seguridad social en españa en 2018

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    En su quinta edición, el Informe “El Derecho del Trabajo y de la Seguridad Social en España 2018” le ofrece una síntesis, que por concreta no es menos rigurosa, de los principales hitos por los que ha transitado el iuslaboralismo a lo largo del último año. En concreto, en las páginas que siguen, los expertos integrantes de la Sección Juvenil de la Asociación Española de Derecho del Trabajo y de la Seguridad Social (AEDTSS) analizan para usted, en primer lugar, las principales resoluciones europeas y nacionales en materia de igualad y no discriminación, acoso en sus más diversas manifestaciones, liberad religiosa y libertad de expresión. Asimismo, se abordan también las cuestiones relativas al empleo y la contratación, casi monopolizadas por el impacto de las plataformas y las consecuencias del caso de Diego. En materia de vicisitudes, sin perder importancia el despido colectivo, observará un cierto auge de los casos relativos a sucesión empresarial, movilidad funcional y empleo público. En el ámbito del derecho colectivo, además de analizarse el IV AENC, encontrará un estudio pormenorizado de las principales resoluciones en materia de libertad sindical, representación unitaria y ultraactividad. La sección relativa a conciliación y corresponsabilidad incluye este año como novedad un apartado relativo a violencia de género, al hilo de los avances normativos derivados del Real Decreto-ley 9/2018. Los epígrafes concernientes a la protección social y la prevención de riesgos laborales crecen de forma significativa en esta edición, lo que ha permitido abordar la evolución jurisprudencial para buena parte de las prestaciones y riesgos previstos en la Ley. Por último, las expertas del apartado de derecho procesal se han encargado de revisar a fondo los casos más significativos en el marco de las modalidades procesales especiales, con especial hincapié en el ámbito concursal. También han abordado la jurisprudencia constitucional más reciente sobre el de recurso de reposición. En suma, tienen ante usted un trabajo científico consolidado en el tiempo y sólido en cuanto al contenido, fiel reflejo de, a pesar del difícil contexto, el buen hacer de la joven doctrina iuslaboralista española

    El Derecho del Trabajo y de la Seguridad Social en España en 2016. Sección Juvenil de la Asociación Española de Derecho del Trabajo y de la Seguridad Social

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    En su quinta edición, el Informe “El Derecho del Trabajo y de la Seguridad Social en España 2018” le ofrece una síntesis, que por concreta no es menos rigurosa, de los principales hitos por los que ha transitado el iuslaboralismo a lo largo del último año. En concreto, en las páginas que siguen, los expertos integrantes de la Sección Juvenil de la Asociación Española de Derecho del Trabajo y de la Seguridad Social (AEDTSS) analizan para usted, en primer lugar, las principales resoluciones europeas y nacionales en materia de igualad y no discriminación, acoso en sus más diversas manifestaciones, liberad religiosa y libertad de expresión. Asimismo, se abordan también las cuestiones relativas al empleo y la contratación, casi monopolizadas por el impacto de las plataformas y las consecuencias del caso de Diego. En materia de vicisitudes, sin perder importancia el despido colectivo, observará un cierto auge de los casos relativos a sucesión empresarial, movilidad funcional y empleo público. En el ámbito del derecho colectivo, además de analizarse el IV AENC, encontrará un estudio pormenorizado de las principales resoluciones en materia de libertad sindical, representación unitaria y ultraactividad. La sección relativa a conciliación y corresponsabilidad incluye este año como novedad un apartado relativo a violencia de género, al hilo de los avances normativos derivados del Real Decreto-ley 9/2018. Los epígrafes concernientes a la protección social y la prevención de riesgos laborales crecen de forma significativa en esta edición, lo que ha permitido abordar la evolución jurisprudencial para buena parte de las prestaciones y riesgos previstos en la Ley. Por último, las expertas del apartado de derecho procesal se han encargado de revisar a fondo los casos más significativos en el marco de las modalidades procesales especiales, con especial hincapié en el ámbito concursal. También han abordado la jurisprudencia constitucional más reciente sobre el de recurso de reposición. En suma, tienen ante usted un trabajo científico consolidado en el tiempo y sólido en cuanto al contenido, fiel reflejo de, a pesar del difícil contexto, el buen hacer de la joven doctrina iuslaboralista española. The fifth edition of the report, "Labour and Social Security Law in Spain in 2018" analyses the key issues in the changing scenario of Labour Law and Social Security during last year. Elaborated by the Young Scholars’ Section of the Spanish Association of Labour and Social Security Law focuses on the following thematic blocks: non-specific fundamental rights; employment contracts and employment; issues related to employment relationship; collective rights; equality and co-responsibility; occupational risks prevention; and procedural law. In conclusion, you may find here a concrete but detailed analysis of the the main legal and case law novelties of Spanish Social Law

    Expediciones Humboldt: Honda-Méndez, Tolima

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    Este informe presenta los resultados de la caracterización biológica de uno de los bosques secos con mejor estado de conservación en el departamento del Tolima, ubicado entre los municipio de Honda, Méndez y Armero-Guayabal. Estos bosques se encuentran en una matriz de ganadería y producción agropecuaria, donde las coberturas boscosas son conservadas por los propietarios, conscientes de la importancia de este ecosistema para la provisión de bienes y servicios ecosistémicos. Esperamos que esta información producto de la capacidad científica del Instituto Humboldt, sea relevante y útil en las decisiones de planificación estratégica tanto en el ordenamiento territorial de los municipios de Honda, Méndez y Armero-Guayabal, como para las decisiones de conservación que se tomen en la regiónBogotáCiencias Básicas de la Biodiversida

    Prospective individual patient data meta-analysis of two randomized trials on convalescent plasma for COVID-19 outpatients

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    Data on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk of hospitalization of outpatients. Two multicenter, double-blind randomized trials (NCT04621123, NCT04589949) were merged with data pooling starting when = 50 years and symptomatic for <= 7days were included. The intervention consisted of 200-300mL of CP with a predefined minimum level of antibodies. Primary endpoints were a 5-point disease severity scale and a composite of hospitalization or death by 28 days. Amongst the 797 patients included, 390 received CP and 392 placebo; they had a median age of 58 years, 1 comorbidity, 5 days symptoms and 93% had negative IgG antibody-test. Seventy-four patients were hospitalized, 6 required mechanical ventilation and 3 died. The odds ratio (OR) of CP for improved disease severity scale was 0.936 (credible interval (CI) 0.667-1.311); OR for hospitalization or death was 0.919 (CI 0.592-1.416). CP effect on hospital admission or death was largest in patients with <= 5 days of symptoms (OR 0.658, 95%CI 0.394-1.085). CP did not decrease the time to full symptom resolution

    Higher COVID-19 pneumonia risk associated with anti-IFN-α than with anti-IFN-ω auto-Abs in children

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    We found that 19 (10.4%) of 183 unvaccinated children hospitalized for COVID-19 pneumonia had autoantibodies (auto-Abs) neutralizing type I IFNs (IFN-alpha 2 in 10 patients: IFN-alpha 2 only in three, IFN-alpha 2 plus IFN-omega in five, and IFN-alpha 2, IFN-omega plus IFN-beta in two; IFN-omega only in nine patients). Seven children (3.8%) had Abs neutralizing at least 10 ng/ml of one IFN, whereas the other 12 (6.6%) had Abs neutralizing only 100 pg/ml. The auto-Abs neutralized both unglycosylated and glycosylated IFNs. We also detected auto-Abs neutralizing 100 pg/ml IFN-alpha 2 in 4 of 2,267 uninfected children (0.2%) and auto-Abs neutralizing IFN-omega in 45 children (2%). The odds ratios (ORs) for life-threatening COVID-19 pneumonia were, therefore, higher for auto-Abs neutralizing IFN-alpha 2 only (OR [95% CI] = 67.6 [5.7-9,196.6]) than for auto-Abs neutralizing IFN-. only (OR [95% CI] = 2.6 [1.2-5.3]). ORs were also higher for auto-Abs neutralizing high concentrations (OR [95% CI] = 12.9 [4.6-35.9]) than for those neutralizing low concentrations (OR [95% CI] = 5.5 [3.1-9.6]) of IFN-omega and/or IFN-alpha 2
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