9 research outputs found
Random variable functions used in hydrology
In this work, expressions of the cumulative distribution function of Y X, Y/X and X/(X + Y ) for continuous dependent random variables with supported on a unbounded and bounded interval are derived. The dependence approach is based on copula functions. Additionally, the methodology is applied to real data on hydrology.En este trabajo, se derivan expresiones de la funciĂłn de distribuciĂłn acumulada de Y X, Y/X y X/(X + Y ) para variables aleatorias dependientes continuas con soporte en un intervalo ilimitado y limitado. El enfoque de dependencia se basa en funciones cĂłpula. Además, la metodologĂa se aplica a datos reales de hidrologĂa
Robust beta regression through the logit transformation
Beta regression models are employed to model continuous response variables in
the unit interval, like rates, percentages, or proportions. Their applications
rise in several areas, such as medicine, environment research, finance, and
natural sciences. The maximum likelihood estimation is widely used to make
inferences for the parameters. Nonetheless, it is well-known that the maximum
likelihood-based inference suffers from the lack of robustness in the presence
of outliers. Such a case can bring severe bias and misleading conclusions.
Recently, robust estimators for beta regression models were presented in the
literature. However, these estimators require non-trivial restrictions in the
parameter space, which limit their application. This paper develops new robust
estimators that overcome this drawback. Their asymptotic and robustness
properties are studied, and robust Wald-type tests are introduced. Simulation
results evidence the merits of the new robust estimators. Inference and
diagnostics using the new estimators are illustrated in an application to
health insurance coverage data
Random variable functions used in hydrology
In this work, expressions of the cumulative distribution function of Y X, Y/X and X/(X + Y ) for continuous dependent random variables with supported on a unbounded and bounded interval are derived. The dependence approach is based on copula functions. Additionally, the methodology is applied to real data on hydrology
Laser-Camera Vision Sensing for Spacecraft Mobile Robot Navigation
The advent of spacecraft mobile robots-free-flyng sensor platforms and communications devices intended to accompany astronauts or remotely operate on space missions both inside and outside of a spacecraft-has demanded the development of a simple and effective navigation schema. One such system under exploration involves the use of a laser-camera arrangement to predict relative positioning of the mobile robot. By projecting laser beams from the robot, a 3D reference frame can be introduced. Thus, as the robot shifts in position, the position reference frame produced by the laser images is correspondingly altered. Using normalization and camera registration techniques presented in this paper, the relative translation and rotation of the robot in 3D are determined from these reference frame transformations
Efeito de composto orgânico sobre a produção e caracterĂsticas comerciais de alface americana Effect of organic compost on crisp head lettuce production and commercial characteristics
Doses de composto orgânico foram avaliadas na produtividade e qualidade da alface americana em um ensaio em TrĂŞs Pontas, de 08/07 a 30/08/02. O delineamento utilizado foi em blocos casualizados com quatro repetições, sendo os tratamentos constituĂdos por cinco doses de composto orgânico (0,0; 20,0; 40,0; 60,0 e 80,0 t ha-1). A massa fresca total evidenciou um efeito quadrático, na qual a produtividade máxima de 914,2 g planta-1, foi obtida com a dose de 59,4 t ha-1 do composto orgânico. Para massa fresca comercial, a máxima produtividade (634,3 g planta-1), foi obtida com a dose de 56,1 t ha-1. A maior circunferĂŞncia da cabeça comercial (41,4 cm), foi obtida com a dose de 53,7 t ha-1. A dose de 42,7 t ha-1 proporcionou um comprimento de caule máximo de 3,9 cm. Diante desses resultados, pode-se concluir que o uso de 56,0 t ha-1 de composto orgânico aplicado em prĂ©-plantio, proporciona aumento de rendimento e qualidade comercial da alface americana.<br>Doses of organic compost were evaluated on crisp head lettuce production and quality in an experiment conduced in TrĂŞs Pontas, Brazil, from July 8>th to August 30th. The experimental design was in randomized complete blocks with four replicates, the treatments being constituted by five doses of organic compost (0.0; 20.0; 40.0; 60.0 and 80.0 t ha-1). Total fresh matter showed a quadratic effect, in which the maximum yield of 914.2 g plant-1 was obtained with the dose of 59.4 t ha-1 of organic compost. For commercial fresh matter, the maximum yield (634.3 g plant-1) was obtained with the dose of 56.1 t ha-1. The greatest commercial head circumference (41.4 cm) was obtained with the dose of 53.7 t ha-1. The dose of 42.7 t ha-1 caused a maximum stem length of 3.9 cm. These results permit to conclude that the use of 56.0 t ha-1 of organic compost applied in pre plant provides an increase in yield and commercial quality of crisp head lettuce
International Nosocomial Infection Control Consortiu (INICC) report, data summary of 43 countries for 2007-2012. Device-associated module
We report the results of an International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2007-December 2012 in 503 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study using the Centers for Disease Control and Prevention's (CDC) U.S. National Healthcare Safety Network (NHSN) definitions for device-associated health care–associated infection (DA-HAI), we collected prospective data from 605,310 patients hospitalized in the INICC's ICUs for an aggregate of 3,338,396 days. Although device utilization in the INICC's ICUs was similar to that reported from ICUs in the U.S. in the CDC's NHSN, rates of device-associated nosocomial infection were higher in the ICUs of the INICC hospitals: the pooled rate of central line–associated bloodstream infection in the INICC's ICUs, 4.9 per 1,000 central line days, is nearly 5-fold higher than the 0.9 per 1,000 central line days reported from comparable U.S. ICUs. The overall rate of ventilator-associated pneumonia was also higher (16.8 vs 1.1 per 1,000 ventilator days) as was the rate of catheter-associated urinary tract infection (5.5 vs 1.3 per 1,000 catheter days). Frequencies of resistance of Pseudomonas isolates to amikacin (42.8% vs 10%) and imipenem (42.4% vs 26.1%) and Klebsiella pneumoniae isolates to ceftazidime (71.2% vs 28.8%) and imipenem (19.6% vs 12.8%) were also higher in the INICC's ICUs compared with the ICUs of the CDC's NHSN