Search results for " Regression"

Familial and Parental Predictors of Physical Activity in Late Adolescence: Prospective Analysis over a Two-Year Period

2021

Children’s health behaviors are highly influenced by their parents and family. This study aimed to prospectively evaluate the parental/familial factors associated with physical activity levels (PALs) among older adolescents. The participants were 766 adolescents, who were prospectively observed at baseline (when they were 16 years of age), at first follow-up measurement (FU1

Regression quantiles to assess higher education performance

2012

From 2001 Italian university system has adopted the credits to mea- sure the workload of the students. The weighted mean of marks with credits as weights is used to measure the their performance. In our opinion it does not seem a proper way to measure. We suggest to adopt the median of the weighted marks, because we are considering an ordinale variable, with a non-normal empir- ical distribution, and a®ected by outliers. Then, instead of using an OLS multiple regression, we investigate the determinants of the performance measured by the median using a regression quantile for ordinal response. A real dataset concerning 133 students of the Faculty of Economics of the University of Palermo is …

Non-crossing quantile regression via monotone B-spline varying coefficients

2019

Quantile regression can be used to obtain a nonparametric estimate of a conditional quantile function. The presence of quantile crossing, however, leads to an invalid distribution of the response and makes it dicult to use the tted model for prediction. In this work, we show that crossing can be alleviated or completely eliminated by explicit modeling of the regression coecients as a function of the percentile values in (0,1). We illustrate the approach via a wellknown dataset by emphasizing dierences with respect to the competitors.

Explaining local governments' cost efficiency: Controllable and uncontrollable factors

2020

Abstract Efficient and effective management of public resources is essential at all levels of government. This issue has gained momentum due to the strains that affected public sector finances after the onset of the 2007/08 crisis in many countries, particularly in Europe. In this article, we evaluate the influence of environmental variables that affect local government efficiency in one European country, Spain, during the crisis years (2009–2015). To this end, and considering the possible influence of both controllable and uncontrollable factors, we use an approach that is able to analyse their impact across the conditional distribution of performance, and which controls for the (likely) e…

Analysis of the determinants of entrepreneurial intention: the case of Burkina Faso

2018

International audience; In this study, we propose to analyze students' entrepreneurial intention, drawing on Lazear's (2004) self-selection model. This model captures the role of "human capital" in employment assignment and emphasizes the importance of the variety of skills in the individual's entrepreneurial orientation. For this purpose, we have a database collected in 2017 from over 1000 students at Ouaga I and Ouaga II universities in Burkina Faso. The results of estimates obtained using the quantile regression method show a positive and significant effect of the diversity of skills on the intention score, mainly at the median level. Even if the effect is not strong, this result support…

Application of selected methods of black box for modelling the settleability process in wastewater treatment plant

2017

The paper described how the results of measurement s of inflow wastewater temperature in the chamber, a degree of external and internal recirculation in the biological-mechanical wastewater treatment plan t (WWTP) in Cedzyna near Kielce, Poland, were used to make predictions of settleability of activated sludge. Three methods,namely: multivariate adaptive regression splines (MARS), random forests (RF) and modified random forests (RF+ SOM) were employed to compute activated sludge settleability. The results of analysis indicate that modified random forests demonstrate the best predictive abilities.

Measuring, comparing and interpreting phenotypic selection on floral scent

2022

Natural selection on floral scent composition is a key element of the hypothesis that pollinators and other floral visitors drive scent evolution. The measure of such selection is complicated by the high-dimensional nature of floral scent data and uncertainty about the cognitive processes involved in scent-mediated communication. We use dimension reduction through reduced-rank regression to jointly estimate a scent composite trait under selection and the strength of selection acting on this trait. To assess and compare variation in selection on scent across species, time and space, we reanalyse 22 datasets on six species from four previous studies. The results agreed qualitatively with prev…

Interlinkages between operational conditions and direct and indirect greenhouse gas emissions in a moving bed membrane biofilm reactor

2016

Nitrous oxide (N2O) can be emitted during wastewater treatment contributing to the global warming due to its high global warming potential,. During the last ten years, several efforts have been provided to improve knowledge on: key mechanisms, operating factors and influent features affecting the N2O production/emission. However, the knowledge on the investigated issues is not completely mature. Indeed, in terms of mathematical modelling, literature shows that a reliable model has not yet been established due to the huge data set required and the complexity of the mechanistic models indicated as the most accurate. In this work, the first attempt to perform a multiregression analysis is pres…

La mobilità dei turisti in Sicilia: aspetti motivazionali e comportamentali.

2013

Paysage et risque sanitaire - Le cas de l'echinococcose alvéolaire. Approche multiscalaire

2005

Echinococcus multilocularis is a parasite of public health importance causing the fatal zoonotic disease alveolar echinococcosis. The parasite's eggs are dispersed in the environment through the fox faeces. Epidemiological issues associated with the disease led to the monitoring of the endemic status in foxes in France and in Europe. Fox faeces collected in the field were tested for the presence of the parasite and assembled in a georeferenced database. GIS-assisted analysis investigated relationships between landscape characteristics and potential risk. Three scale levels were successively explored. In the french Doubs département located in a high endemicity area, binary logistic regressi…