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Search Results: 1 - 10 of 196859 matches for " D; Gutiérrez "
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Guaranteed Model Order Estimation and Sample Complexity Bounds for LDA
E. D. Gutiérrez
Statistics , 2013,
Abstract: The question of how to determine the number of independent latent factors (topics) in mixture models such as Latent Dirichlet Allocation (LDA) is of great practical importance. In most applications, the exact number of topics is unknown, and depends on the application and the size of the data set. Bayesian nonparametric methods can avoid the problem of topic number selection, but they can be impracticably slow for large sample sizes and are subject to local optima. We develop a guaranteed procedure for topic number recovery that does not necessitate learning the model's latent parameters beforehand. Our procedure relies on adapting results from random matrix theory. Performance of our topic number recovery procedure is superior to hLDA, a nonparametric method. We also discuss some implications of our results on the sample complexity and accuracy of popular spectral learning algorithms for LDA. Our results and procedure can be extended to spectral learning algorithms for other exchangeable mixture models as well as Hidden Markov Models.
Viabilidad financiera para el establecimiento de un sistema de producción estabulado de carne bovina
Carlos Díaz Gutiérrez
Tecnología en Marcha , 2009,
Abstract: Se presentan los resultados económicos de la ganadería de carne bovina, mediante el sistema de producción intensiva en estabulación. La investigación se desarrolló en la zona del distrito de Pejibaye, cantón de Jiménez, provincia de Cartago. Participó un total de cincuenta y dos productores interesados en la implementación de una actividad productiva no tradicional en la zona y de alta demanda e intensidad de recursos disponibles en finca. Se logró clasificar las diferentes unidades productivas según sus características, estableciéndose, de acuerdo con la propuesta tecnológica, los requerimientos de inversión y las demandas de costos operativos. La generación de esa información permitió evaluar los modelos según las técnicas de presupuesto de capital, con los correspondientes indicadores de viabilidad financiera sobre la inversión. Dada la limitación de recursos disponibles en finca y en la zona, se demuestra, en la evaluación, el bajo potencial de este tipo de sistema productivo, al obtenerse indicadores de viabilidad financiera en los modelos negativos.
Tecnologías del cuerpo: Una clave de lectura en dos textos de Francisco Rivas Technologies of the body: Reading key in two Francisco Rivas's texts
Pia Gutiérrez Díaz
Acta Literaria , 2011,
Abstract:
Sistema constructivo Quincha Prefabricada
Díaz Gutiérrez, Aníbal
Informes de la Construccion , 1984,
Abstract: Prefabricated cane lathing basically involves the use of frames of sawn timber, filled with round wattle, cane and strips of bamboo, all plaited together so that they can be placed and fixed in the frame without nails being required. Once these panels have been assembled and fixed in place to provide walls, they are covered with a mixture of mud and straw forming a primary layer, and finally, they are given a top layer using such material as mud, cement, plaster and other substances, depending on preferences, costs and climatic or other conditions to which the wall is to be exposed, or on the preferences of the user. A light roof is used for roofing, based on a wooden support structure and a covering made of cane and a mud cast packed with straw. For regions of high rainfall, planks of asbestos and cement, zinc or other materials are fixed over the mud cast. La Quincha Prefabricada consiste básicamente en el empleo de bastidores de madera aserrada, rellenados con ca izo redondo, ca a brava, tiras de bambú, todos ellos colocados en el bastidor en forma trenzada para su auto fijación sin necesidad de usar clavos; estos paneles, después de ser montados y fijados en sitio constituyendo paredes, son revocados con barro mezclado con paja, formando una primera capa; y, finalmente, reciben una última capa de revoque utilizándose materiales como el barro, cemento, yeso u otros, dependiendo de las preferencias, costos, de las condiciones climatológicas u otras a las que estará expuesta la pared o de las preferencias del usuario. Como techado se emplea un techo liviano a base de una estructura portante de madera y cobertura de ca a y torta de barro con paja. Para zonas de alta precipitación pluvial se fija, sobre la torta de barro, planchas de asbesto-cemento, planchas de zinc u otras.
Application of Hybrid-Electric Power Supply System in Fishing Vessels
Gutiérrez C.,Meana D.
EPJ Web of Conferences , 2012, DOI: 10.1051/epjconf/20123304009
Abstract: In a clear commitment for sustainability in the fisheries sector, Regional Administration for Economy and Industry of Xunta de Galicia and EnergyLab Technology Centre signed a cooperation agreement with the goal of performing a demonstration project based on the application of hybrid power supply systems in a fishing vessel. Such a project aims to analyze the feasibility of implementing hybridelectric powertrain systems in the Galician coastal fleet. The final purpose is the implementation of more efficient and environmental friendly propulsion systems within the marine industry. The project scope consists in defining a technical solution for the replacement of diesel propulsion system in a standard fishing vessel (12m. long), representative of the Galician inshore fleet, by a hybrid-electric system powered by three different types of energy sources.
Anoxic sediments off Central Peru record interannual to multidecadal changes of climate and upwelling ecosystem during the last two centuries
M. Graco, D. Gutiérrez,L. Farías
Advances in Geosciences (ADGEO) , 2006,
Abstract: The coastal region of central Chile (36° S) is one of the most productive coastal systems, characterized by a marked seasonality in the upwelling regime, that brings subsurface waters rich in nutrient and poor in oxygen (ESSW) into the euphotic zone. This oceanographic condition depends basically on the equatorward wind strength and is modified on different time scales, with the El Ni o-Southern Oscillation (ENSO) phenomenon as the main source of interannual variability in the Pacific Ocean. Here we present an effort to integrate physical and biogeochemical variability associated with in situ information and experiments at coastal stations off central Chile (36° S) in order to improve the knowledge on the pelagic-benthic coupling in this upwelling system during the warm ENSO phase or El Ni o. Carbon fluxes exported from the water column to the sediments and the ammonium exchange across the sediment-water interface are discussed together with oceanographic and benthic conditions. All measurements and estimations were carried out from May 1997 until April 2001 at two stations, one located inside Concepción Bay (~28 m depth), and the other on the continental shelf at ~36° S (~88 m depth). The results show that the pelagic and benthic systems are strongly coupled off central Chile (36° S). Oceanographic variability associated with upwelling events (seasonal scale) and an El Ni o event (interannual scale) was observed. The carbon fluxes exported to the sediments, the benthic conditions (i.e., quantity and quality of the sediment organic matter), and the ammonium exchange across the sediment-water interface, responded to the seasonal regime of upwelling during non El Ni o years as well as to the ENSO related oceanographic variability.
Respuesta mecánica durante la inversión de la deformación en caliente de un acero microaleado
Badiola, D. J.,Gutiérrez, I.
Revista de Metalurgia , 2005,
Abstract: The mechanical behaviour of a Nb-microalloyed steel under non monotonie conditions has been studied using double hit hot torsion tests involving changes in the twist direction. For strain reversal conditions, a clear mechanical transient has been observed. This transient has been characterized by a steep hardening region just after reversal which takes place up to a stress level near the one reached before reversing, then a region showing a low strain hardening rate and finally, a region extending up to the convergence of monotonie and reversal behaviours. Testing temperatures and strain rates have ranged from 950°C to 1200°C and from 0.01s-1 to 0.1s-1, respectively. Applied prestrains before reversal have varied from 0.03 to 0.25 in order to avoid the occurrence of dynamic recrystallization during previous strain. Lastly, some relationships have been established between the deformation conditions and the parameters defining the transient. These parameters depend mainly on the prestrain. Se ha estudiado el comportamiento mecánico de un acero microaleado con niobio bajo condiciones no monótonas de deformación mediante ensayos de torsión en caliente de doble pasada con cambio de sentido de giro entre la primera y la segunda de ellas. Se ha observado que la inversión de la deformación produce un transitorio en las curvas de fluencia caracterizado por un endurecimiento rápido hasta alcanzar un nivel de tensión menor al que se tenía, justo, antes de aplicar el cambio en el sentido de giro, una etapa de endurecimiento nulo y, finalmente, una región en la que el comportamiento mecánico durante la inversión tiende progresivamente al comportamiento mecánico monótono. Las temperaturas de ensayo se han variado entre 950 °C y 1.200 °C y las velocidades de deformación entre 0,01 y 0,1 s-1 Las deformaciones previas aplicadas antes de la reversión han estado comprendidas entre 0,03 y 0,25, evitándose la interacción con la recristalización dinámica. Finalmente, se han establecido diferentes relaciones entre las condiciones de deformación y los parámetros que definen el transitorio, observándose que estos últimos dependen principalmente de la deformación previa a la inversión.
Neoliberal globalization and its repercussions on education
Enrique Javier Díez Gutiérrez
Revista Electronica Interuniversitaria de Formación del Profesorado , 2010,
Abstract: Neo-liberalism has become the backdrop to the changes in world-wide educational policy, which are no longer limited to cut-backs in resources or privatisation but which actually affect the very core of educational theory and pedagogical politics on a fundamental level. The conflicts which spill over into the school represent part of a more generalised crisis in politics and citizenship in global capitalism. Using the argument that education should meet the demands of society, an evidently reductionalist interpretation is made by which society sees school and university solely in terms of their usefulness to business, and centres education around the preparation of the type of professionals demanded by companies. According to this philosophy, investment in education and the curriculum should be tailored to meet the needs of the market, and seen as a preparation for the labour market. The social role of education, as a training ground for democracy and citizenship, is now seen as a waste of public funds, and has been replaced by the view private companies have of the function of education: as a training ground for meeting the needs of business. A “flexible” and “multi-purpose” employee thus constitutes the new ideal reference point for pedagogy.
Estrategias de intervención socioeducativa con alumn@s en conflicto en programas de garantía social
Enrique Javier Díez Gutiérrez
Indivisa : Boletin de Estudios e Investigación , 2000,
Abstract:
Current state of knowledge about data treatment techniques of position-time in the field of the motor system in biomechanics Estado Actual de de conocimientos de las técnicas de tratamiento de los datos posición - tiempo en el campo de la biomecánica del aparato locomotor
K. Gianikellis,M. Gutiérrez Dávila
Motricidad : European Journal of Human Movement , 2010,
Abstract: ABSTRACT Measurements made using an image - based motion analysis system are contaminated with noise generated during the recording and digitizing procedures. So the sampled signal can be considered as the sum of a quantity of true information associated to the physical phenomenon that is taking place and a quantity of information, that is nothing to do with this, representing the systematic and random noise induced by lens distortion, erroneous marker placement, calibration errors, skin and marker movements, digitizing errors, digitizer resolution, etc. Due to the nature of numerical differentiation, unless the random noise is reduced it may be amplified to such an order that the estimated derivative values may contain more error than signal. The main purpose of this study is the introduction of the reader to the most important techniques to treat de position -time data in order to reduce the noise and differentiate the displacement data. Besides, objective criteria are defined to select the most efficient fit data technique in Biomechanics. KEY WORDS: data processing, curve fitting, Splines, digital filtering, Fourier Series, Kinematics El objetivo de este estudio es presentar, en líneas generales, el estado actual de conocimientos respecto a las técnicas de tratamiento de los datos posición -tiempo que se utilizan en la investigación en el campo de la Biomecánica para describir, analizar y evaluar el movimiento humano. La evolución de estas técnicas ha permitido disponer de información cada vez más fiable respecto a la cinemática de los marcadores anátomicos de interés de cuya calidad dependen mucho las inferencias posteriores que se hacen respecto a la eficacia de los patrones motores que se estudian. Una de las principales aportaciones de este trabajo es establecer criterios que permiten seleccionar objetivamente entre las diferentes técnicas de "ajuste" de los datos posición - tiempo para mejorar la relación "se al - ruido" y calcular su primera y la segunda derivada con mayor precisión. PALABRAS CLAVE: Tratamiento de se ales, funciones spline, filtrado digital, análisis Fourier, análisis cinemático.
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