Search results for "Sampling"
showing 10 items of 788 documents
Variabilidad geográfica de la violencia contra las mujeres en España
2010
OBJETIVOS: Describir la prevalencia global y por comunidades autónomas (CC.AA.) de la violencia por un compañero íntimo, sus características y la violencia fuera de la pareja, así como estudiar la relación entre la prevalencia de violencia por un compañero íntimo y la frecuencia de denuncias y muertes por este motivo. MÉTODOS: Encuesta transversal mediante cuestionario autoadministrado en 11.475 mujeres que acuden a consultas de atención primaria durante los años 2006 – 2007. Diseño muestral estratificado y polietápico, con una muestra representativa por CA. Además de la violencia por un compañero íntimo y la violencia fuera de la pareja, se recogieron denuncias y muertes por la primera. Se…
An efficient method for subcutaneous veins localization using Near Infrared imaging
2014
In the majority of the medical treatments, intravenous catheterization is the most important phase in which skilled medical practitioners locate the best vein and perform catheterization process for medication or blood sampling. Due to the different physiological characteristics, mainly darker skin tone, scars or dehydrated condition of patients, medical staff stumbles in localization of veins. This paper proposes an enhanced method which intends to overcome the difficulty faced by medical staff in veins localization for intravenous catheterization. Using the Near Infrared imaging and image processing algorithms a novel approach for veins visualization is proposed. In order to have complete…
Iontophoresis for Therapeutic Drug Delivery and Non-invasive Sampling Applications
2017
Most research concerning iontophoresis has focused on topical and transdermal drug delivery and in non-invasive skin sampling applications. Iontophoresis has been established as a safe, versatile and efficient enhancement technique, and several iontophoretic devices have been marketed for topical (lidocaine) and systemic (fentanyl, sumatriptan) delivery and for non-invasive sampling (glucose). Nevertheless, the last decade has seen an increased interest into the potential use of iontophoresis to deliver drugs through the nail and through the sclera and cornea, the two main barriers to eye drug delivery. This chapter aims to summarize the main progress achieved in these areas.
Pesticide occurrence in the waters of Júcar River, Spain from different farming landscapes.
2017
A combined methodology to identify and quantify farming chemicals in the entire Júcar River basin has been developed. The procedure consisted of the application of environmental forensic criteria associating laboratory analytical samples, cartographic analysis using Geographical Information Systems (GIS) and synthetic statistical analysis. Sampling involved the collection of 15 samples in surface waters distributed alongside the Júcar River and its two main tributaries (Cabriel and Magro Rivers). The analytical procedure involves generic sample extraction and selective determination of up to 50 target pesticides by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Geogra…
The continuous sample of working lives: Improving its representativeness
2017
This paper studies the representativeness of the Continuous Sample of Working Lives (CSWL), a set of anonymized microdata containing information on individuals from Spanish Social Security records. We examine several CSWL waves (2005–2013) and show that it is not representative for the population with a pension income. We then develop a methodology to draw a large dataset from the CSWL that is much more representative of the retired population in terms of pension type, gender and age. This procedure also makes it possible for users to choose between goodness of fit and subsample size. In order to illustrate the practical significance of our methodology, the paper also contains an applicatio…
The 90-day oscillations of Jupiter’s Great Red Spot revisited
2000
Abstract We have analyzed a large set of ground-based CCD images covering the period from 1993 to early 1999, to address the current status and behavior of the 90-day longitudinal oscillations of the Jovian Great Red Spot (GRS). The good temporal sampling of these data have been complemented with a small set of high resolution Hubble Space Telescope images. The average zonal velocity of the GRS from 1994 to 1998 was −3.8 ms−1 with extreme values of −2.4 and −4.2 ms−1 in 1993–1994 resulting from the interactions with nearby features. Our study confirms the existence of the longitudinal oscillations with a mean period of 89.8±0.15 days and an amplitude of 1.2±0.7°. The oscillations survived t…
Estructura dimensional de las competencias del siglo XXI en los estudiantes universitarios de educación
2018
La nueva Sociedad del Conocimiento requiere nuevas competencias, que son conocidas como Competencias del siglo XXI. Estas competencias se subdividen en competencias de pensamiento y competencias de orden superior en tecnologías de información y comunicación. El objetivo de este artículo es determinar la estructura dimensional de las competencias del siglo XXI, junto con los factores personales clave en este sentido. Se trata de un estudio correlacional, basado en un diseño de encuesta, cuya muestra está constituida por estudiantes de los grados de Pedagogía y Educación Social de la Universidad de Valencia, seleccionados por muestreo no probabilístico y accidental, recogiendo la información …
Variance estimation and asymptotic confidence bands for the mean estimator of sampled functional data with high entropy unequal probability sampling …
2013
For fixed size sampling designs with high entropy it is well known that the variance of the Horvitz-Thompson estimator can be approximated by the H\'ajek formula. The interest of this asymptotic variance approximation is that it only involves the first order inclusion probabilities of the statistical units. We extend this variance formula when the variable under study is functional and we prove, under general conditions on the regularity of the individual trajectories and the sampling design, that we can get a uniformly convergent estimator of the variance function of the Horvitz-Thompson estimator of the mean function. Rates of convergence to the true variance function are given for the re…
Analyzing the impact of using the SRP (Simplified roughness parameterization) method on soil moisture retrieval over different regions of the globe
2015
International audience; This paper focuses on a new approach to account for soil roughness effects in the retrieval of soil moisture (SM) at L-band in the framework of the SMOS (Soil Moisture and Ocean Salinity) mission: the Simplified Roughness Parameterization (SRP). While the classical retrieval approach considers SM and τ nad (vegetation optical depth) as retrieved parameters, this approach is based on the retrieval of SM and the TR parameter combining τ nad and soil roughness (TR τ nad + Hr /2). Different roughness parameterizations were tested to find the best correlation (R), bias and unbiased RMSE (ubRMSE) when comparing homogeneous retrievals of SM and in situ SM measurements carri…
Comparison of sampling methods for semipelagic animals in two deep basins of Lake Saimaa
1996
The efficiency of different methods for sampling semipelagic animals was compared in the deep basins of Lake Paasivesi and Lake Puruvesi of the complex Lake Saimaa, Finland, during 1990–92. Certain semipelagic animals, such as Mysis relicta, amphipods and larvae of Chaoborus flavicans, are important bioindicators of water and benthic quality. However, owing to their high mobility and vertical migrations they are difficult to sample quantitatively with traditional benthic methods.