521 research outputs found

    A Saturated Output Feedback Controller for the Three Phase Voltage Sourced Reversible Boost Type Rectifier

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    In this article, we present a saturating controller to regulate the output voltage load in a three phase Boost type rectifier. The controller only needs the output voltage signal to be implemented. Moreover, by forcing the inductance currents to track desired suitable sinusoidal signals in phase with the input source voltages, the controller can ensure a near the unity power factor functioning of the system. The saturation feature in this controller is motivated by the fact that the allowed combinations of switches in the rectifier circuit define a finite set of allowed control vectors, moreover, the convex combinations of these vectors raise up a convex hull in the space of control inputs, an hexagon in this example. Thus, based upon the assumption of fast switching, we can ensure that any control vector lying inside this hexagon, and much more, inside its inscrit circle, can be physically implementable by means of a PWM strategy or a convex combination of the allowed control vectors.

    A Saturated Output Feedback Controller for the Three Phase Voltage Sourced Reversible Boost Type Rectifier

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    Inspecting Maude Variants with GLINTS

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    [EN] This paper introduces GLINTS, a graphical tool for exploring variant narrowing computations in Maude. The most recent version of Maude, version 2.7.1, provides quite sophisticated unification features, including order-sorted equational unification for convergent theories modulo axioms such as associativity, commutativity, and identity. This novel equational unification relies on built-in generation of the set of variants of a term t, i.e., the canonical form of t sigma for a computed substitution sigma. Variant generation relies on a novel narrowing strategy called folding variant narrowing that opens up new applications in formal reasoning, theorem proving, testing, protocol analysis, and model checking, especially when the theory satisfies the finite variant property, i.e., there is a finite number of most general variants for every term in the theory. However, variant narrowing computations can be extremely involved and are simply presented in text format by Maude, often being too heavy to be debugged or even understood. The GLINTS system provides support for (i) determining whether a given theory satisfies the finite variant property, (ii) thoroughly exploring variant narrowing computations, (iii) automatic checking of node embedding and closedness modulo axioms, and (iv) querying and inspecting selected parts of the variant trees.This work has been partially supported by EU (FEDER) and Spanish MINECO grant TIN 2015-69175-C4-1-R and by Generalitat Valenciana PROMETEO-II/2015/013. Angel Cuenca-Ortega is supported by SENESCYT, Ecuador (scholarship program 2013), and Julia Sapina by FPI-UPV grant SP2013-0083. Santiago Escobar is supported by the Air Force Office of Scientific Research under award number FA9550-17-1-0286.Alpuente Frasnedo, M.; Cuenca-Ortega, A.; Escobar Román, S.; Sapiña-Sanchis, J. (2017). Inspecting Maude Variants with GLINTS. Theory and Practice of Logic Programming. 17(5-6):689-707. https://doi.org/10.1017/S147106841700031XS689707175-

    DIAGNÓSTICO DE INDICADORES DE CALIDAD FÍSICO-QUÍMICA DEL AGUA EN AFLUENTES DEL RÍO ATOYAC - DIAGNOSIS OF INDICATORS OF PHYSICAL-CHEMICAL QUALITY OF WATER IN AFFLUENTS OF THE ATOYAC RIVER

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    En la Región de Texmelucan, Pue., las principales fuentes de agua para riego provienen del deshielo de los volcanes y de pozos profundos; estas fuentes satisfacen las necesidades de agua del área agrícola de Texmelucan y sus alrededores. Sin embargo, alrededor de 350 productores también emplean aguas residuales para regar sus cultivos. Se evaluaron algunos parámetros que inciden en la calidad físico-química del agua cuando se utiliza con fines de riego (pH, CE, Ca2+, Mg2+, K+, PO42-, SO42-, CO32-, HCO3-, Na+, B y Cl-). Se realizó un muestreo aleatorio en 28 puntos, en afluentes del cauce del Río Atoyac, donde se tomaron muestras de agua para realizar el análisis físico-químico correspondiente. Los resultados muestran que la CE osciló entre 0 y 0.875 dS m-1; el 64.28% correspondió a aguas de baja salinidad y bajo contenido de sodio (clase C1S1), el 28.57% a aguas con salinidad media y bajo contenido de sodio (clase C2S1) y el 7.15% a aguas de salinidad alta y bajo contenido de sodio (clase C3S1). En promedio, el Ca (0.98 meq L-1) y Mg (1.11 meq L-1) estuvieron presentes en mayor concentración, lo que modificó favorablemente los valores de la relación de adsorción de sodio (RAS). Los iones bicarbonato (HCO3-) en el agua presentaron una media de 1.83 meq L-1. La concentración de Cl-, HCO3-, CO3-2, B y SO4-2 no ha afectado a los cultivos establecidos y la concentración de PO42- es un aporte significativo a los cultivos. Estos resultados indican que la región de Texmelucan, Pue., tiene agua apta para el riego desde el punto de vista físico-químico; sin considerar el contenido de metales pesados ni análisis biológicos de la misma

    A predictive model and risk factors for case fatality of covid-19

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    This study aimed to create an individualized analysis model of the risk of intensive care unit (ICU) admission or death for coronavirus disease 2019 (COVID-19) patients as a tool for the rapid clinical management of hospitalized patients in order to achieve a resilience of medical resources. This is an observational, analytical, retrospective cohort study with longitudinal follow-up. Data were collected from the medical records of 3489 patients diagnosed with COVID-19 using RT-qPCR in the period of highest community transmission recorded in Europe to date: February–June 2020. The study was carried out in in two health areas of hospital care in the Madrid region: the central area of the Madrid capital (Hospitales de Madrid del Grupo HM Hospitales (CH-HM), n = 1931) and the metropolitan area of Madrid (Hospital Universitario Príncipe de Asturias (MH-HUPA) n = 1558). By using a regression model, we observed how the different patient variables had unequal importance. Among all the analyzed variables, basal oxygen saturation was found to have the highest relative importance with a value of 20.3%, followed by age (17.7%), lymphocyte/leukocyte ratio (14.4%), CRP value (12.5%), comorbidities (12.5%), and leukocyte count (8.9%). Three levels of risk of ICU/death were established: low-risk level (20%). At the high-risk level, 13% needed ICU admission, 29% died, and 37% had an ICU–death outcome. This predictive model allowed us to individualize the risk for worse outcome for hospitalized patients affected by COVID-19

    Development

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    Mitosis is controlled by multiple kinases that drive cell cycle progression and prevent chromosome mis-segregation. Aurora kinase B interacts with survivin, borealin and incenp to form the chromosomal passenger complex (CPC), which is involved in the regulation of microtubule-kinetochore attachments and cytokinesis. Whereas genetic ablation of survivin, borealin or incenp results in early lethality at the morula stage, we show here that aurora B is dispensable for CPC function during early cell divisions and aurora B-null embryos are normally implanted. This is due to a crucial function of aurora C during these early embryonic cycles. Expression of aurora C decreases during late blastocyst stages resulting in post-implantation defects in aurora B-null embryos. These defects correlate with abundant prometaphase figures and apoptotic cell death of the aurora B-deficient inner cell mass. Conditional deletion of aurora B in somatic cells that do not express aurora C results in chromosomal misalignment and lack of chromosome segregation. Re-expression of wild-type, but not kinase-dead, aurora C rescues this defect, suggesting functional overlap between these two kinases. Finally, aurora B-null cells partially arrest in the presence of nocodazole, suggesting that this kinase is not essential for the spindle assembly checkpoint

    Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

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    Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV
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