Search results for "SAMPLE"
showing 10 items of 2270 documents
Revista electrónica de investigación y evaluación educativa
2021
Background of INCASI Project H2020-MSCA-RISE-2015 GA 691004. WP1: Compilation Este artículo tiene dos objetivos. En primer lugar, queremos analizar si el peso del origen social de los graduados universitarios influye en la inserción laboral, tomando como indicador los ingresos que obtienen los titulados que trabajan, cuando controlamos la titulación obtenida. En segundo lugar, intentamos observar si los graduados universitarios provenientes de orígenes sociales más desfavorecidos se encuentran más desocupados y más inactivos que los provenientes de hogares con más recursos. Para tal fin analizamos a los titulados que egresaron de universidades públicas catalanas en el curso 2006-2007, entre…
Stochastic Approximation for Multivariate and Functional Median
2010
We propose a very simple algorithm in order to estimate the geometric median, also called spatial median, of multivariate (Small (1990)) or functional data (Gervini (2008)) when the sample size is large. A simple and fast iterative approach based on the Robbins-Monro algorithm (Duflo (1997)) as well as its averaged version (Polyak and Juditsky (1992)) are shown to be effective for large samples of high dimension data. They are very fast and only require O(Nd) elementary operations, where N is the sample size and d is the dimension of data. The averaged approach is shown to be more effective and less sensitive to the tuning parameter. The ability of this new estimator to estimate accurately …
Application of multivariate statistics to the problems of upper palaeolithic and mesolithic samples
1987
Multivariate statistics (discriminant function analysis and principal component analysis) have been applied to a broad sample of Upper Paleolithic and mesolithic skulls. In addition to some methodological problems concerning the evaluation of missing data by principal component analysis, we discussed the possibility of misclassifications (14%).
2019
Objective A short questionnaire which can be applied for assessing patient satisfaction in different contexts and different countries is to be developed. Methods Six items addressing tangibles, reliability, responsiveness, assurance, empathy, and communication were analysed. The first five items stem from SERVQUAL (SERVice QUALity), the last stems from the discussion about SERVQUAL. The analyses were performed with data from 12 surveys conducted in six different countries (England, Finland, Germany, Greece, the Netherlands, Spain) covering two different conditions (type 2 diabetes, stroke). Sample sizes for included participants are 247 in England, 160 in Finland, 231 in Germany, 152 in Gre…
Multivariate Exploratory Comparative Analysis of LaLiga Teams: Principal Component Analysis
2021
The use of principal component analysis (PCA) provides information about the main characteristics of teams, based on a set of indicators, instead of displaying individualized information for each of these indicators. In this work we have considered reducing an extensive data matrix to improve interpretation, using PCA. Subsequently, with new components and with multiple linear regression, we have carried out a comparative analysis between the best and bottom teams of LaLiga. The sample consisted of the matches corresponding to the 2015/16, 2016/17 and 2017/18 seasons. The results showed that the best teams were characterized and differentiated from bottom teams in the realization of a great…
Health literacy of pregnant women and duration of breastfeeding maintenance: a feasibility study
2020
Research the association between health literacy (HL) and exclusive breastfeeding at 4-months postpartum.Despite the benefits of breastfeeding (BF), its rates are low worldwide. Among the reasons for abandonment is the level of maternal education. Maternal education has been associated with HL, but evidence between HL and BF maintenance is limited.A cross-sectional study.The sample compromised 229 nursing mothers recruited from January 2018 to the end of December 2018 at Spain by systematic sampling method. Women were interviewed postpartum on parameters associated with the start and continuation of BF up to 4 months postpartum. Multivariate logistic regression models to explain exposure va…
Combination of mid- and near-infrared spectroscopy for the determination of the quality properties of beers
2006
Abstract The combination of infrared (MIR) and near-infrared (NIR) spectroscopy has been employed for the determination of important quality parameters of beers, such as original and real extract and alcohol content. A population of 43 samples obtained from the Spanish market and including different types of beer, was evaluated. For each technique, spectra were obtained in triplicate. In the case of NIR a 1 mm pathlength quartz flow cell was used, whereas attenuated total reflectance measurements were used in MIR. Cluster hierarchical analysis was employed to select calibration and validation data sets. The calibration set was composed of 15 samples, thus leaving 28 for validation. A critic…
A new sample of large angular size radio galaxies I. The radio data
2001
We present a new sample of 84 large angular size radio galaxies selected from the NRAO VLA Sky Survey. Radio sources with declination above +60 degrees, total flux density greater than 100 mJy at 1.4 GHz and angular size larger than 4 arcmin have been selected and observed with the VLA at 1.4 and 4.9 GHz. The radio observations attempt to confirm the large angular size sources and to isolate the core emission for optical identification. In this paper, the first of a series of three, we present radio maps of 79 sources from the sample and discuss the effects of the selection criteria in the final sample. 37 radio galaxies belong to the class of giants, of which 22 are reported in this paper …
Three Peculiar Objects From a New Sample of Radio Galaxies
2001
We have constructed a new sample of 84 large angular size radio galaxies selected from the NRAO VLA Sky Survey (NVSS). Radio sources with declination above +60°, total flux density greater than 100 mJy at 1.4 GHz and angular size larger then 4′ have been selected and observed with the VLA at 1.4 and 4.9 GHz. A number of peculiar radio galaxies have been discovered, of which we present here results on J1835+620, J2114+820 and J2157+664.
Investor Inattention to All-Cash Acquisition Announcements: A Joint Day-Time Analysis in the Spanish Market
2021
Prior studies suggest that investors have limited attention, which determines the speed with which information is incorporated into share prices and, in turn, affects the efficiency of the markets. Unlike other corporate events, the information contained in an acquisition announcement is generally less standard and more complicated to process. Therefore, investor inattention is less likely around this event. In this study we test the existence of investor inattention for a sample of all-cash acquisition announcements of listed and unlisted target firms released by listed Spanish firms from 1998 to 2018. Cash acquisitions allow us to control for the strategic behavior of overvalued companies…