Statistics and Computing - To overcome the inherent limitations of axis-aligned base learners in ensemble learning, several methods of rotating the feature space have been discussed in the... 相似文献
Urban Ecosystems - Loss and fragmentation of semi-natural grasslands have had negative consequences for grassland biodiversity, such as butterflies. Urban parks and other urban green spaces have so... 相似文献
This article uses a new multidimensional indicator to measure precariousness among young workers across all EU-28 countries. This indicator measures both the incidence and intensity of precariousness. The analysis has involved five dimensions: wages, type of contract, type of working day, disempowerment, and job insecurity. Our database is the European Union Labour Force Survey for the period 2009–2016. The main indication of precariousness is low wages. We find high rates of precariousness for Mediterranean countries (because of low wages and temporary contracts), Denmark (low wages), and the Netherlands (expansion of involuntary part-time jobs). Central European countries have moderate rates, and most Continental and Eastern countries have low rates. We also find that a higher level of education is related to a lower probability of having a precarious job. Finally, we find a greater probability of having a precarious job among women in most countries, and non-statistically significant differences by country of birth.
Activity and species-specific responses of insectivorous bats in different urban-forest conditions provides a general perspective on the adaptability and vulnerability of bat species towards urbanization intensity. Here we evaluated species richness and activity patterns of aerial insectivorous bats across an urbanized landscape in the highlands of Chiapas, in Mexico. Acoustic monitoring of echolocation calls was conducted for 27 nights over a period of four months. Species richness and relative activity of insectivorous bats were estimated in a landscape with different conditions of urbanization intensity: urban areas, non-urban and forest areas. We identified a total of 14 bat species and three phonotypes. Bat species richness and relative activity was similar (X2 = 0.568, gl = 2, p > 0.05), but species composition differed among conditions. We observed a significant higher occurrence of Bauerus dubiaquercus, Eptesicus brasiliensis and Myotis californicus in forest sites. Urban sites presented higher occurrence of Molossus rufus and phonotype Molossidae 2, while non-urban sites presented a higher occurrence of Eptesicus furinalis and phonotype Molossidae 2. We were able to identify bat species according to their relative activity in relation todifferent landscape conditions. Species of the Molossidae family presented the highest activity in urban sites, which was positively affected by the number of streetlights, while species of the Vespertilionidae presented the highest activity in forest sites, which was positively related totree density. While urbanization tends to diminish native biodiversity and alter faunal communities, our results show a similar richness and relative activity of aerial insectivorous bats along the urban ecosystem. The effect of urbanization intensity becomes more apparent in species-specific bat activity; the response of species towards particular habitat conditions depends on local habitat quality and characteristics (i.e., presence of streetlights, vegetation cover and tree density). 相似文献
General guidelines are offered for the successful engagement of Latino families in family therapy. It is suggested that a therapist's involvement of Latinos in therapy requires both skills in family therapy and sensitivity to cultural issues. Factors found to be useful in the family assessment are presented. Furthermore, issues in the engagement and evaluation phases of family therapy with Latino families are discussed, and illustrative clinical material is presented. 相似文献
\(\alpha \)-Stable distributions are a family of probability distributions found to be suitable to model many complex processes and phenomena in several research fields, such as medicine, physics, finance and networking, among others. However, the lack of closed expressions makes their evaluation analytically intractable, and alternative approaches are computationally expensive. Existing numerical programs are not fast enough for certain applications and do not make use of the parallel power of general purpose graphic processing units. In this paper, we develop novel parallel algorithms for the probability density function and cumulative distribution function—including a parallel Gauss–Kronrod quadrature—, quantile function, random number generator and maximum likelihood estimation of \(\alpha \)-stable distributions using OpenCL, achieving significant speedups and precision in all cases. Thanks to the use of OpenCL, we also evaluate the results of our library with different GPU architectures. 相似文献
In this paper, we present a multivariate version of the skewed log-Birnbaum–Saunders regression model. This new family of distributions holds good properties such as marginal variables following univariate skewed log-Birnbaum–Saunders distributions, besides presenting the usual log-Birnbaum–Saunders distribution as a particular case. Furthermore, the model parameters are estimated through maximum-likelihood methods, a closed-form expression for the Fisher’s information matrix is presented, and testing hypothesis for model parameters is performed. Two real datasets are analyzed and results are discussed. 相似文献
During the last quarter of the nineteenth century, nonprofit kindergartens exhibited many modern characteristics such as comprehensive services, community outreach, and developmentally appropriate practices. By the beginning of this century, most of those modern characteristics had been eliminated as kindergartens became integrated into the public school system. This article analyzes the institutional reorganization of nonprofit kindergartens under public control by applying and extending Thomas H. Jeavons's framework. The author argues that the observed institutional reorganization was caused by adaptation to the legitimizing principles of the public sector. It is important to understand this dynamic well to correctly assess the effects of public funding and ownership on nonprofit organizations. This article is especially relevant to those following policy arguments for public funding of preschool programs. 相似文献
ABSTRACTRandom vectors with positive components are common in many applied fields, for example, in meteorology, when daily precipitation is measured through a region Marchenko and Genton (2010Marchenko, Y., Genton, M. (2010). Multivariate log-skew-elliptical distributions with applications to precipitation data. Environmetrics 21:318–340.[Crossref], [Web of Science ®], [Google Scholar]). Frequently, the log-normal multivariate distribution is used for modeling this type of data. This modeling approach is not appropriate for data with high asymmetry or kurtosis. Consequently, more flexible multivariate distributions than the log-normal multivariate are required. As an alternative to this distribution, we propose the log-alpha-power multivariate and log-skew-normal multivariate models. The first model is an extension for positive data of the fractional order statistics model Durrans (1992Durrans, S. (1992). Distributions of fractional order statistics in hydrology. Water Resour. Res. 28:1649–1655.[Crossref], [Web of Science ®], [Google Scholar]). The second one is an extension of the log-skew-normal model studied by Mateu-Figueras and Pawlowsky-Glahn (2007Mateu-Figueras, G., Pawlowsky-Glahn, V. (2007). The skew-normal distribution on the simplex. Commun. Stat.-Theory Methods 36:1787–1802.[Taylor & Francis Online], [Web of Science ®], [Google Scholar]). We study parameter estimation for these models by means of pseudo-likelihood and maximum likelihood methods. We illustrate the proposal analyzing a real dataset. 相似文献
Urban Ecosystems - We studied the occurrence of bats in urban parks in the city of Madrid (Spain), and the resulting patterns were compared with bat occurrence in the surrounding region. In this... 相似文献