Search results for "Variables"
showing 10 items of 578 documents
Detection of explanation obstacles in scientific texts: the effect of an understanding task vs. an experiment task
2013
The aim of this study is to analyse the effect of tasks on the detection of explanation obstacles when secondary school students read scientific texts. Students were instructed to read short passages under different task conditions, and to ask questions if necessary. Obstacle detection was operationalised in terms of the type of questions asked by the students. The experiment examined the influence of goals associated with the task of reading to understand a text vs. reading to perform a procedure described by the text (a science experiment). Significantly, more explanation obstacles were found in the understanding condition than in the experiment condition. Scientific text also had an effe…
Predicting bond betas using macro-finance variables
2019
We conduct in-sample and out-of-sample forecasting using the new approach of combining explanatory variables through complete subset regressions (CSR). We predict bond CAPM betas and bond returns conditioning on various macro-finance variables. We explore differences across long-term government bonds, investment grade corporate bonds, and high-yield corporate bonds. The CSR method performs well in predicting bond betas, especially in-sample, and, mainly high-yield bond betas when the focus is out-of-sample. Bond returns are less predictable than bond betas.
Eco-Efficiency of the English and Welsh Water Companies: A Cross Performance Assessment
2021
Analyzing costs and greenhouse gas (GHG) emissions could be of great importance for the water utilities to supply water services in a healthy and sustainable manner. In this study, we measured the eco-efficiency of several water utilities in England and Wales by incorporating GHG as an undesirable output. For the first time, we evaluated the eco-efficiency of the water production process using robust cross-efficiency data envelopment analysis (DEA) techniques. The further use of clustering and regression techniques allowed us to better understand the drivers of eco-efficiency. The results showed that the mean eco-efficiency of the water sector was 0.748, which indicates that costs and GHG e…
Quasihyperbolic boundary condition: Compactness of the inner boundary
2011
We prove that if a metric space satisfies a suitable growth condition in the quasihyperbolic metric and the Gehring–Hayman theorem in the original metric, then the inner boundary of the space is homeomorphic to the Gromov boundary. Thus, the inner boundary is compact. peerReviewed
Gromov hyperbolicity and quasihyperbolic geodesics
2014
We characterize Gromov hyperbolicity of the quasihyperbolic metric space (\Omega,k) by geometric properties of the Ahlfors regular length metric measure space (\Omega,d,\mu). The characterizing properties are called the Gehring--Hayman condition and the ball--separation condition. peerReviewed
Predictors of Job Satisfaction among Staff in Residential Settings for Persons with Intellectual Disabilities: A Comparison between Three Residential…
2010
Background This cross-sectional study aims to assess whether there are differences in staff job satisfaction, including organizational and individual characteristics, between three residential models for adults with intellectual disabilities (small residential home, group home and institution) and to investigate the organizational and individual variables associated with staff job satisfaction. Methods A standardized self-administered questionnaire (Job Satisfaction Survey) was distributed together with demographic questions between April 2007 and June 2007. In total, 1301 staff members completed the questionnaire. Results We found that staff working at small homes had a significantly hi…
Hardy spaces and quasiconformal maps in the Heisenberg group
2023
We define Hardy spaces $H^p$, $00$ such that every $K$-quasiconformal map $f:B \to f(B) \subset \mathbb{H}^1$ belongs to $H^p$ for all $0<p<p_0(K)$. Second, we give two equivalent conditions for the $H^p$ membership of a quasiconformal map $f$, one in terms of the radial limits of $f$, and one using a nontangential maximal function of $f$. As an application, we characterize Carleson measures on $B$ via integral inequalities for quasiconformal mappings on $B$ and their radial limits. Our paper thus extends results by Astala and Koskela, Jerison and Weitsman, Nolder, and Zinsmeister, from $\mathbb{R}^n$ to $\mathbb{H}^1$. A crucial difference between the proofs in $\mathbb{R}^n$ and $\mathbb{…
Socio-environmental variables and transmission risk of lymphatic filariasis in central and northern Mozambique
2013
Lymphatic filariasis (LF) is endemic in Mozambique, where it is caused by Wuchereria bancrofti with Culex quinquefasciatus as the main vector. It affects approximately 10% of the population (2 million) with about 16 million at risk. Prevalence rates in 40 out of 65 districts that together comprise the four endemic provinces Niassa, Cabo Delgado, Nampula and Zambezia were analysed with the aim of elucidating the socio-environmental variables influencing the transmission. The levels of prevalence were divided into six ranks and certain climatic, environmental and social factors were considered independent variables. A climadiagram was created and the LF risk and the water budget-based index w…
Socio-Ecological Correlates of Physical Activity in Children with Autism Spectrum Disorder: A Cross-Sectional Study in Spain
2021
This study aims to analyse the Physical Activity(PA) levels of a group of children with ASD and explore certain socio-ecological variables that may be correlated with these levels. The participants of this cross-sectional study were 20 boys and 5girls with ASD, aged between 4 and 14 years. A socio-demographic questionnaire was designed expressly to obtain socio-demographic data, and PA levels were measured with a triaxial accelerometer (ActiGraph, wGT3X-BT).After performing a descriptive analysis, we analysed the relationship between the variables through Spearman correlations and performed the Kruskal Wallis test to compare the results of moderate, vigorous and very vigorous PA according t…
Stability of radial symmetry for a Monge-Ampère overdetermined problem
2008
Recently the symmetry of solutions to overdetermined problems has been established for the class of Hessian operators, including the Monge-Ampère operator. In this paper we prove that the radial symmetry of the domain and of the solution to an overdetermined Dirichlet problem for the Monge-Ampère equation is stable under suitable perturbations of the data. © 2008 Fondazione Annali di Matematica Pura ed Applicata and Springer-Verlag.