994 resultados para ATE estimator


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Thesis (Master's)--University of Washington, 2016-06

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The generalized secant hyperbolic distribution (GSHD) proposed in Vaughan (2002) includes a wide range of unimodal symmetric distributions, with the Cauchy and uniform distributions being the limiting cases, and the logistic and hyperbolic secant distributions being special cases. The current article derives an asymptotically efficient rank estimator of the location parameter of the GSHD and suggests the corresponding one- and two-sample optimal rank tests. The rank estimator derived is compared to the modified MLE of location proposed in Vaughan (2002). By combining these two estimators, a computationally attractive method for constructing an exact confidence interval of the location parameter is developed. The statistical procedures introduced in the current article are illustrated by examples.

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This paper investigates the performance analysis of separation of mutually independent sources in nonlinear models. The nonlinear mapping constituted by an unsupervised linear mixture is followed by an unknown and invertible nonlinear distortion, are found in many signal processing cases. Generally, blind separation of sources from their nonlinear mixtures is rather difficult. We propose using a kernel density estimator incorporated with equivariant gradient analysis to separate the sources with nonlinear distortion. The kernel density estimator parameters of which are iteratively updated to minimize the output independence expressed as a mutual information criterion. The equivariant gradient algorithm has the form of nonlinear decorrelation to perform the convergence analysis. Experiments are proposed to illustrate these results.

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Factors associated with duration of dementia in a consecutive series of 103 Alzheimer's disease (AD) cases were studied using the Kaplan-Meier estimator and Cox regression analysis (proportional hazard model). Mean disease duration was 7.1 years (range: 6 weeks-30 years, standard deviation = 5.18); 25% of cases died within four years, 50% within 6.9 years, and 75% within 10 years. Familial AD cases (FAD) had a longer duration than sporadic cases (SAD), especially cases linked to presenilin (PSEN) genes. No significant differences in duration were associated with age, sex, or apolipoprotein E (Apo E) genotype. Duration was reduced in cases with arterial hypertension. Cox regression analysis suggested longer duration was associated with an earlier disease onset and increased senile plaque (SP) and neurofibrillary tangle (NFT) pathology in the orbital gyrus (OrG), CA1 sector of the hippocampus, and nucleus basalis of Meynert (NBM). The data suggest shorter disease duration in SAD and in cases with hypertensive comorbidity. In addition, degree of neuropathology did not influence survival, but spread of SP/NFT pathology into the frontal lobe, hippocampus, and basal forebrain was associated with longer disease duration. © 2014 R. A. Armstrong.

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2000 Mathematics Subject Classification: Primary: 62M10, 62J02, 62F12, 62M05, 62P05, 62P10; secondary: 60G46, 60F15.

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2000 Mathematics Subject Classification: 62J12, 62F35

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2010 Mathematics Subject Classification: 62F12, 62M05, 62M09, 62M10, 60G42.

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2000 Mathematics Subject Classification: 62G07, 60F10.

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We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 +/- 0.7 (stat) +/- 6.7 (syst) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

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We evaluate phosphorus (P) and biogenic barium (bio-Ba) as nutrient burial and export productivity indicators for the Late Cretaceous and early Paleogene, combining these with calcium carbonate (CaCO3), organic carbon (C), and bulk CaCO3 C isotopes (d13C). Sample ages span 36-71 Ma (~1 sample/0.5 m.y.) for a depth transect of sites in the western North Atlantic (Blake Nose, Ocean Drilling Program Leg 171B, Sites 1052, 1051, and 1050). We use a multitracer approach including redox conditions to investigate export productivity surrounding the global Paleocene d13C maximum (~57 Ma). Reducing conditions render most of the bio-Ba record not useful for export productivity interpretations. P and organic C records indicate that regional nutrient and organic C burial were high at ~61 and ~69 Ma, and low during the Paleocene d13C maximum, a time of proposed global high relative organic C burial. Observed organic C burial changes at Blake Nose cannot explain this C isotope excursion.

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With the objective to improve the reactor physics calculation on a 2D and 3D nuclear reactor via the Diffusion Equation, an adaptive automatic finite element remeshing method, based on the elementary area (2D) or volume (3D) constraints, has been developed. The adaptive remeshing technique, guided by a posteriori error estimator, makes use of two external mesh generator programs: Triangle and TetGen. The use of these free external finite element mesh generators and an adaptive remeshing technique based on the current field continuity show that they are powerful tools to improve the neutron flux distribution calculation and by consequence the power solution of the reactor core even though they have a minor influence on the critical coefficient of the calculated reactor core examples. Two numerical examples are presented: the 2D IAEA reactor core numerical benchmark and the 3D model of the Argonauta research reactor, built in Brasil.

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Alexandre Jose de Melo Moraes (1816-1882), foi medico Historiador e politico brasileiro. Revela-se como autor de um Compêndio de historia no ano de 1854, quando publica a obra Ensaio corografico do imperio do Brasil. O sucesso da obra levou-o a mudar radicalmente o rumo de seu interesse de assuntos tão diversos como a Medicina, Botanica e Agricultura para a Historia. Mello Moraes não tinha formação de historiador nem jamais se dedicara a pesquisa historica, porem legou seu nome a posteridade como um dos maiores amealhadores de documentos historicos relevantes. Sua obra e recheada de preocupações politicas assemelhou a tarefa de historiador a de um juiz que censura, mostra os defeitos, acusa os crimes ou louva as virtudes para a posteridade. Foi considerado um Grande colecionador e pesquisador.

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Segundo Borba de Moraes, é um "compêndio de informações gerais sobre ruas, edifícios, monumentos, comércio, nos dias do Império (principalmente na Capital). Contém muitos dados históricos. Segundo Sacramento Blake, "saiu neste ano [1879] a primeira parte com o retrato do Censelheiro Joaquim Marcelino de Brito a quem é oferecida a obra, contendo uma planta da cidade do Rio de Janeiro, e no fim um grande quadro com a geografia histórica do Brasil, e a segunda , em 1882."