Search results for "CORRELATION"
showing 10 items of 2282 documents
Psychometric properties of the Norwegian version of the Kidscreen-27 questionnaire
2016
Background The Norwegian version of the Kidscreen-27, a measure of generic health-related quality of life, has not yet been validated. Thus, the aim of this study was to investigate the reliability and validity of the Norwegian Kidscreen-27, in 10 year-old children. Methods The Kidscreen-27 consists of five domains and was validated in a cross-sectional study of 1085 school children (52.5 % boys). In addition a subsample of 56 children also had repeated measures in order to study test-retest reliability. Results Cronbach's alpha values ranged from 0.73 to 0.83, while intraclass correlation values over time ranged from 0.71 to 0.81. The domains of physical well-being, psychological well-bein…
Heritability of Lung Function: A Twin Study Among Never-Smoking Elderly Women
2011
Most studies on lung function heritability have been conducted in smokers and non-smokers using cross-sectional study design. Smoking patterns may, however, confound the contribution of genetic factors. We investigated heritability of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio longitudinally, excluding the effects of smoking. A sample of never smoking female twins (n = 374), aged 63–76 at baseline, answered health questionnaires and attended spirometry in years 2000 and 2003. Bivariate structural equation modeling, restricted to adequate spirometry performances (baseline n = 339, follow-up n = 252), was used to estimate genetic and environ…
Econométrie spatiale (2, Hétérogénéité spatiale)
2000
Spatial econometric methods aim at taking into account the two special characteristics of spatial data: spatial autocorrelation, which is the lack of independence between geographical observations, and spatial heterogeneity, which is related to the differentiation of variables and behaviors in space. These techniques have been mostly developed the last ten years and are more often applied in empirical studies with geographical data. The aim of this article is to present the way spatial autocorrelation and spatial heterogeneity can be incorporated in regression relationships and to present the estimation and inference procedures adapted to the models incorporating these two effects. This art…
Convergence of European regions (an approach by spatial econometrics)
2000
The aim of this paper is the analysis of spatial dependence in convergence processes applied to European regions. First, we apply the recently developed exploratory spatial data analysis (Anselin, 1996) in order to describe more precisely the geographical dynamics of European regional income growth patterns. New insights are brought to the usual cr-convergence measure, which hides geographical patterns that may fluctuate over time. Second, we test the presence of spatial autocorrelation in /^-convergence models by using spatial econometrics methods (Anselin, 1988 ; Anselin and Florax, 1995). We compare the results with and without spatial autocorrelation in order to assess the effect of geo…
Does Exist A Correlation Between BMI and Gleason Patterns 4 and 5 At Prostate Biopsy?
2013
Background: Obesity has been related with higher Gleason grade and worse prognosis. Increasing proportion of Gleason pattern 4 or 5 is a critical factor for biochemical recurrence, progression and mortality. The endocrine activity of visceral fat could be responsible of the differentation of the prostatic malignant cell towards a more aggressive fenotype. The aim of our study was to correlate Body Mass Index with the presence of Gleason pattern 4 or higher at biopsy. Materials and Methods: Consecutive patients with positive prostate biopsy were included. A transrectal prostate biopsy procedure with 12 cores, was performed. All tissue samples were reviewed. Results: Out of 135 patients diagn…
Spatial autocorrelation and the selection of simultaneous autoregressive models
2007
Aim Spatial autocorrelation is a frequent phenomenon in ecological data and can affect estimates of model coefficients and inference from statistical models. Here, we test the performance of three different simultaneous autoregressive (SAR) model types (spatial error = SAR err , lagged = SAR lag and mixed = SAR mix ) and common ordinary least squares (OLS) regression when accounting for spatial autocorrelation in species distribution data using four artificial data sets with known (but different) spatial autocorrelation structures. Methods We evaluate the performance of SAR models by examining spatial patterns in model residuals (with correlograms and residual maps), by comparing model para…
Adaptación y estudio de las propiedades psicométricas del Cuestionario de consecuencias de consumo de alcohol en jóvenes, forma breve, en muestra esp…
2020
El objetivo de este trabajo es presentar la adaptación y estudio de las propiedades psicométricas del Cuestionario de consecuencias de consumo de alcohol en jóvenes, forma breve (B-YAACQ) en una muestra de 323 estudiantes de Psicología españoles, de los cuales el 74.3% son mujeres. Se realizó una retro-traducción de los ítems siguiendo las normas de la ITC, y un análisis factorial confirmatorio (AFC) con el programa Mplus mediante el método de extracción WLSMV y la matriz de correlaciones policóricas. El AFC arrojó resultados satisfactorios sobre el modelo unidimensional, con muy buenos indicadores de ajuste. Todas las saturaciones factoriales presentaron valores adecuados y fueron estadíst…
Weighted Likelihood Function of Multiple Statistical Parameters to Retrieve 2D TRUS-MR Slice Correspondece for Prostate Biopsy
2012
International audience; This paper presents a novel method to identify the 2D axial Magnetic Resonance (MR) slice from a pre-acquired MR prostate volume that closely corresponds to the 2D axial Transrectal Ultrasound (TRUS) slice obtained during prostate biopsy. The shape-context representations of the segmented prostate contours in both the imaging modalities are used to establish point correspondences using Bhattacharyya distance. Thereafter, Chi-square distance is used to find the prostate shape similarities between the MR slices and the TRUS slice. Normalized mutual information and correlation coefficient between the TRUS and MR slices are computed to find the information theoretic simi…
Combining Value and Momentum: Evidence from the Nordic Equity Market
2018
This is the first paper that explores Fisher, Shah and Titman’s (2016) average ranking approach for the value and momentum strategy in the Nordic equity market offering an exceptional experimental environment. Our results indicate that in the Nordic stock markets, the value anomaly offered excess returns in the 1993 to 2017 sample period only when small stocks were a part of the portfolio, whereas the momentum effect is strong and significant, irrespective of size. Interestingly, our findings also indicate that the negative correlation between value and momentum (Asness, Moskowitz and Pedersen, 2013) seems to be driven by growth stocks: Winner stocks that are value stocks generated 1.66% pe…
Renewable Energy Sources in the Baltic States and New Business Approach of the Sector
2021
Renewable energy sources (RES) are efficient in meeting the demand for clean and affordable energy. The need for RES is undeniable and has many advantages but there are also some challenges that need to be taken into consideration and adapted to the energy system. One of the challenges is RES volatility and its impact on electricity prices and power system operation. Europe is trending to power system decentralisation through the involvement of local authorities, active consumers and citizens in the system operation. This article provides main information about the energy sector of Latvia and RES in the Baltic countries. It proposes a methodology for the complex analysis of correlation and …