2,577 research outputs found

    A family of smooth controllers for swinging up a pendulum

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    Es el primer envío que hago. Le agradeceré si me confirma que es todo correcto, especialmente el cumplimiento de los derechos de propiedad de la editorial. Mi email es [email protected] paper presents a new family of controllers for swinging up a pendulum. The swinging up of the pendulum is derived from physical arguments based on two ideas: shaping the Hamiltonian for a system without damping; and providing damping or energy pumping in relevant regions of the state space. A family of simple smooth controllers without switches with nice properties is obtained. The main result is that all solutions that do not start at a zero Lebesgue measure set converge to the upright position for a wide range of the parameters in the control law. Thus, the swing-up and the stabilization problems are simultaneously solved with a single, smooth law. The properties of the solution can be modified by the parameters in the control law. Control signal saturation can also be taken into account using the Hamiltonian approach.MCyT-FEDER DPI2006-0733

    Radar track segmentation with cubic splines for collision risk models in high density terminal areas

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    This paper presents a method to segment airplane radar tracks in high density terminal areas where the air traffic follows trajectories with several changes in heading, speed and altitude. The radar tracks are modelled with different types of segments, straight lines, cubic spline function and shape preserving cubic function. The longitudinal, lateral and vertical deviations are calculated for terminal manoeuvring area scenarios. The most promising model of the radar tracks resulted from a mixed interpolation using straight lines for linear segments and spline cubic functions for curved segments. A sensitivity analysis is used to optimise the size of the window for the segmentation process

    Cultural Preservation of Ethnomedicine in Peru

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    In conjunction with the Minority Health & Health Disparities International Research Training program at San Diego State University, three Linfield students contributed to the ongoing Peru Ethnomedical Project in Trujillo, Peru by: Conducting surveys in two neighborhoods on the edge of the city; Creating a medicinal plant garden in the Chan Chan archaeological site museum. Surveys conducted in Moche, Trujillo were part of a larger study supervised by anthropologists Douglas Sharon and Thomas Love. The research aims to evaluate the usage of medicinal plants in rural and urban Peruvian communities. Linfield’s contribution focused on the creation of the medicinal garden to serve as a community model and educational program. The overall purpose of the 2015 summer faculty collaborative project was to: Preserve the knowledge of these practices; Analyze the plant properties; Publish the information; Provide the community with a garden that reflects the commonly used plants; Educate new generations; Bring back and apply this knowledge in the Linfield community

    Algunas notas sobre arqueología y colonialismo : la zona española del protectorado marroquí, 1912-1945

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    A lo largo de la primera mitad del siglo XX se desarrollaron en el Norte de Marruecos y en el seno de la administración conjunta hispano-marroquí del Protectorado ejercido por España sobre dichos territorios las estructuras de gestión del Patrimonio Arqueológico de dicha Zona. En los párrafos de este artículo abordaremos el paulatino proceso de construcción de dichas estructuras, que marchó en paralelo al desarrollo de los trabajos de investigación de campo y, en buena medida, de forma subsiguiente a los mismos.Through the several decades belonging to the first half of the XXth Century, the territories of North Marocco, placed under the Spanish Protectorate since the Conference of Algeciras in 1906, experienced the development of real public structures devoted to the management of that area’s Archaeological Heritage. We shall focus on this phenomenon, which is closely related to the development of archaeological research in itself as well

    Aportaciones a la flora vascular de la provincia de Córdoba, II (Andalucía, España)

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    En el presente estudio corológico se aportan 25 taxones que son raros o suponen novedad para alguna comarca o toda la provincia de Córdoba (Andalucía, España). Los taxones más interesantes son Campanula decumbens subsp. baetica Cano-Maqueda & Talavera, Narcissus × susannae Fern. Casas y Plumbago auriculata Lam., ya que son citados por primera vez para esta provincia.Twenty-five taxa are recorded as rare and new localities either in some areas or the whole province of Cordoba (Andalusia, Spain). Campanula decumbens subsp. baetica Cano-Maqueda & Talavera, Narcissus × susannae Fern. Casas and Plumbago auriculata Lam. are the most interesting taxa found, being the first record for this province

    Las lenguas en las sociedades del conocimiento

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    Languages become a strategic resource for information and knowledge societies. By expressing and sharing knowledge by means of languages, every culture generates deposits of knowledge, which can be transferred and exchanged among different epistemic communities. The contemporary technologies of information and communication have changed the structure of knowledge flows. Globalization of knowledge poses a great challenge to every language, including the Spanish one. In order to survive in the digital world, they should develop technolanguages. The lemma “Thinking in Spanish” implies a new model of governance for the Ibero-American knowledge communities.En las sociedades de la información y el conocimiento las lenguas se convierten en un recurso estratégico. Al expresar y compartir conocimiento por medio de los idiomas, las culturas generan yacimientos de conocimiento, que pueden ser transferidos e intercambiados entre comunidades epistémicas diferentes. Las actuales tecnologías de la información y la comunicación han cambiado la estructura de los flujos de conocimiento. La globalización del conocimiento plantea un gran desafío a todas las lenguas, incluyendo la española. Para sobrevivir en el mundo digital, los lenguajes han de convertirse en tecnolenguajes. El lema “Pensar en español” aporta un nuevo modelo de gobernanza para las comunidades iberoamericanas del conocimiento

    Calidad de la Tithonia diversifolia en una zona del Valle del Cauto

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    13 páginas, 5 tablas.This experiment was carried out with the objective of determining the nutritive value of Tithonia diversifolia to different bud ages during the two periods of the year. A 0.5 ha field was used, where a standardization cut at 15 cm high from the soil was applied at the beginning of each period. The ages taken into consideration were 60, 120 and 180 days, and the elements evaluated were the RP, the fibrous fractioning, the dry matter In vitro digestibility, the wall cell digestibility and the tanins. To this purpose, a random- block design with three treatments and four repetitions was used through the application of a double classification analysis, and the average results were compared by means of the multiple ranges Duncan test. The statistical program utilized was Statiics version 6.0 for Windows. In the chapter that deals with the analysis of the results, it is evident that the dry matter, NDF, ADF, ADL, Hemicellulous, TF, TCT, CTAF and FTC increased their content (29. 47 %, 50. 51 %, 32. 12 %, 32. 12 %, 18. 39 %, 6.47, 13. 11, 10. 12, and 2. 99 g/kg respectively) at the age of 180 days, whereas the raw protein, the cellulous, the cell content, the In vitro digestibility and the wall cell digestibility decreased with their highest value (28.95, 21.08, 56.34, 78.59 y 76.61 %) at the age of 60 days. As a conclusion, age had a marked effect on the behavior of the evaluated elements, which was stronger during the rainy season, decreasing the nutritive quality.Trabajo realizado con financiación del Programa de Cooperación Interuniversitaria e Investigación Científica de la Agencia Española de Cooperación Internacional para el Desarrollo (Proyecto AECID A/023167/09).Peer Reviewe

    Association of increased Visfatin/PBEF/NAMPT circulating concentrations and gene expression levels in peripheral blood cells with lipid metabolism and fatty liver in human morbid obesity

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    BACKGROUND AND AIMS: Nicotinamide phosphoribosyltransferase (NAMPT) is an adipokine with physiological effects on the control of glucose homeostasis as well as potentially involved in inflammation. The association of circulating NAMPT concentrations with obesity has not been clearly established. The aim of the present work was to evaluate the effect of obesity on circulating concentrations and gene expression levels of NAMPT in human peripheral blood cells (PBCs) as well as its involvement in inflammation, glucose and lipid metabolism. METHODS AND RESULTS: Forty-four serum samples obtained from 14 lean and 30 obese volunteers were used to analyse the circulating concentrations of NAMPT. In addition, PBC, omental adipose tissue (OM) and liver biopsy samples obtained from a subgroup of subjects were used to determine transcript levels of NAMPT by Real-time PCR. Glucose and lipid profile as well as several inflammatory factors and hepatic enzymes were analysed. NAMPT circulating concentrations (P<0.01) and gene expression levels in PBC (P<0.05) were significantly increased in obese patients as compared to lean subjects. Total-cholesterol (P=0.016), HDL-cholesterol (P=0.036) and triglycerides (P=0.050) were significant and independent determinants of circulating concentrations of NAMPT (P<0.01). Moreover, a positive correlation (P<0.01) was found with the hepatic enzymes alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase after BMI adjustment. CONCLUSION: Our work shows that NAMPT circulating concentrations and mRNA expression levels in PBC are increased in obese patients and that plasma NAMPT levels are related to inflammation, lipid metabolism and hepatic enzymes suggesting a potential involvement in fatty liver disease and in the obesity-associated inflammatory stat
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