3,831 research outputs found

    MRAC + H∞ fault tolerant control for linear parameter varying systems

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    Presentado al SysTol 2010 celebrado en Niza del 6 al 8 de octubre.Two different schemes for Fault Tolerant Control (FTC) based on Adaptive Control, Robust Control and Linear Parameter Varying (LPV) systems are proposed. These schemes include a Model Reference Adaptive Controller for an LPV system (MRAC-LPV) and a Model Reference Adaptive Controller with a H¿ Gain Scheduling Controller for an LPV system (MRAC-H¿ GS-LPV). In order to compare the performance of these schemes, a Coupled-Tank system was used as testbed in which two different types of faults (abrupt and gradual) with different magnitudes and different operating points were simulated. Results showed that the use of a Robust Controller in combination with an Adaptive Controller for an LPV system improves the FTC schemes because this controller was Fault Tolerant against sensor fault and had an accommodation threshold for actuator fault magnitudes from 0 to 6Peer Reviewe

    Estudios preliminares sobre la respuesta del trébol blanco (Trifolium repens), inoculado con rhizobium, a la fertilización con boro en la Sabana de Bogotá.

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    En la Sabana de Bogotá se han encontrado deficiencias de B, se hace un ensayo en invernadero, en bloques al azar, para conocer la respuesta de la leguminosa asociada más común de las pasturas, el trébol blanco, inoculado y no inoculado con Rhizobium, a las aplicaciones de 0, 1, 2, 3 y 4 kg/ha de B. Se utilizaron muestras de la capa arabla de las series Techo, Tibaitatá y rio Bogotá. Se hicieron 3 cortes de trébol y para cada corte se determinó el B del suelo soluble en agua caliente, B y N de la parte aérea del trébol. Los suelos de las series río Bogotá y Tibaitatà presentaron igual capacidad de absorción de B y de magnitud inferior a la de la serie Techo. La respuesta en rendimiento fue mayor en las plantas inoculadas. Los valores de B extraídos con agua caliente, no presentan ninguna relación con los rendimientos del trébol. El B aplicado al suelo aumentó el contenido de N en la planta, tanto en las inoculadas como en las no inoculadas. Los rendimientos más altos por corte se encontraron asociados con contenidos de B en la planta de 25 a 35 ppm. La serie con mayor limitación por B aprovechable es Techo, que con aplicaciones de 2 kg/ha produce los más altos rendimientos. La serie río Bogotá presenta respuesta positiva en rendimientos a la aplicación de 2 kg/ha. En la serie Tibaitatá no se encuentra respuesta al B, aunque es posible que con un mayor número de cortes, se encuentre dicha respuest

    The Effect of Pre-Harvest Application of Pectic Oligosaccharides and Abscisic Acid on Technological Ripening and Anthocyanin Profile of ‘Syrah’ Must and Grapes Grown in a Warm Climate

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    The progressive increase of environmental temperature as a consequence of climate change is a challengefor the wine industry. Elevated temperatures during grape ripening affect the development of grape skincolor by inhibiting the synthesis of pigments and promoting their degradation, which causes an imbalancein the chromatic quality of must and red wine. The application of pectic oligosaccharides (POs) and abscisicacid (ABA) triggers the phenylpropanoid pathway and increases the color index in grapes. Since the atharvestpigments and phenolic compounds are determinant for wine quality, this work addressed the preharvestapplication of POs and ABA as an in-field strategy for improving the quality of Syrah must andgrapes grown in a warm climate. The color development, physicochemical parameters, phenolic content,and pigments in berries and must were evaluated. Results showed POs and ABA improved berry colordevelopment and anthocyanin content during ripening. Musts from POs-treated berries exhibited thehighest phenols concentration and the most intense color, related to higher chroma values and anthocyanincontent, particularly delphinidin, petunidin, and malvidin 3-glucosides, while ABA improved must tonalityby reducing the hue angle. In summary, POs and ABA application at veráison, differentially modulatedthe technological ripening of Syrah grapes and can be an alternative to conventional agrochemicals topreserve the quality of musts elaborated from grapes grown in warm climates, by increasing the content ofphenolic compounds and enhancing berry skin color development through the differential accumulationof anthocyanins

    A Light Calibration System for the ProtoDUNE-DP Detector

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    A LED-based fiber calibration system for the ProtoDUNE-Dual Phase (DP) photon detection system (PDS) has been designed and validated. ProtoDUNE-DP is a 6x6x6 m3 liquid argon time-projection-chamber currently being installed at the Neutrino Platform at CERN. The PDS is based on 36 8-inch photomultiplier tubes (PMTs) and will allow triggering on cosmic rays. The system serves as prototype for the PDS of the final DUNE DP far detector in which the PDS also has the function to allow the 3D event reconstruction on non-beam physics. For this purpose an equalized PMT response is desirable to allow using the same threshold definition for all PMT groups, simplifying the determination of the trigger efficiency. The light calibration system described in this paper is developed to provide this and to monitor the PMT performance in-situ.Comment: 15 pages, 5 figure

    Development and validation of a new methodological platform to measure behavioral, cognitive, and physiological responses to food interventions in real time

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    To fully understand the causes and mechanisms involved in overeating and obesity, measures of both cognitive and physiological determinants of eating behavior need to be integrated. Effectively synchronizing behavioral measures such as meal micro-structure (e.g., eating speed), cognitive processing of sensory stimuli, and metabolic parameters, can be complex. However, this step is central to understanding the impact of food interventions on body weight. In this paper, we provide an overview of the existing gaps in eating behavior research and describe the development and validation of a new methodological platform to address some of these issues. As part of a controlled trial, 76 men and women self-served and consumed food from a buffet, using a portion-control plate with visual stimuli for appropriate amounts of main food groups, or a conventional plate, on two different days, in a random order. In both sessions participants completed behavioral and cognitive tests using a novel methodological platform that measured gaze movement (as a proxy for visual attention), eating rate and bite size, memory for portion sizes, subjective appetite and portion-size perceptions. In a sub-sample of women, hormonal secretion in response to the meal was also measured. The novel platform showed a significant improvement in meal micro-structure measures from published data (13 vs. 33% failure rate) and high comparability between an automated gaze mapping protocol vs. manual coding for eye-tracking studies involving an eating test (ICC between methods 0.85; 90% CI 0.74, 0.92). This trial was registered at Clinical Trials.gov with Identifier NCT03610776

    Cumplimiento, conocimiento y automedicación como factores asociados a los resultados clínicos negativos de la farmacoterapia

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    The patient plays a fundamental role in the attainment of good results in pharmacotherapy. Noncompliance,self-medication, or insufficient knowledge of the therapy being employed may provide asource for the causes of these negative clinical outcomes, otherwise known as medicine related problems(MRP). he Dader method was used in the evaluation, identification and classification of MRP. Theassociation of variables was established through the statistical Chi square test. Patient knowledge of themedicine, degree of compliance to therapy and self-medication were studied as causes of the negativeoutcomes encountered. 2556 patients were interviewed throughout the year that the study took place,giving a total of 2261 of valid cases. 33% presented an MRP as the cause of his/her visit to the hospitalemergency ward. Knowledge of the medicine, compliance and self-medication were only studied in thepopulation that presented an MRP and in this work it is demonstrated that these are aspects that areassociated with different dimensions of MRP. It is not possible to establish an association between theexistence or not of negative clinical outcomes in patients with the factors of knowledge of medication,compliance and self-medication. This is due to the fact that these variables are not attributable to thepatient himself, but rather are associated with the characteristics of each medicine.El paciente juega un papel primordial en la consecución de los resultados terapéuticos. El incumplimiento,la automedicación, o la falta de conocimiento del la farmacoterapia pueden ser causas de esosresultados clínicos negativos, denominados en ocasiones problemas relacionados con medicamentos(PRM). El método Dáder se utilizó para la evaluación, identificación y clasificación de PRM. Laasociación de variables se estableció mediante el estadístico chi cuadrado. El conocimiento de la medicación,el cumplimiento y la automedicación fueron estudiados como causa de estos resultados negativosde la medicación. Fueron entrevistados 2556 pacientes durante el año de estudio, resultando 2261 casosválidos. El 33 % presentaron un PRM como causa de visita a urgencias. El conocimiento de la medicación,el cumplimiento y la automedicación fueron estudiados solo en la población que presentó unPRM y se demuestra que son aspectos asociados a las distintas dimensiones de PRM. No es posibleestablecer asociación entre la existencia o no de resultados clínicos negativos en los pacientes con elconocimiento de la medicación, el cumplimiento y la automedicación, debido a que estas variables noson atributos del paciente sino que están asociadas a cada medicamento
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