Search results for " correlation"
showing 10 items of 1380 documents
Bose-Einstein correlations in W-pair decays
2000
Bose-Einstein correlations are studied in semileptonic (WW --> q (q) over bar lv) and fully hadronic (WW --> q (q) over bar q (q) over bar) W-pair decays with the ALEPH detector at LEP at centre-of-mass energies of 172, 183 and 189 GeV. They are compared with those made at the Z peak after correction for the different flavour compositions. A Monte Carlo model of Bose-Einstein correlations based on the JETSET hadronization scheme was tuned to the Z data and reproduces the correlations in the WW --> q (q) over bar lv events. The same Monte Carlo reproduces the correlations in the WW --> q (q) over bar q (q) over bar channel assuming independent fragmentation of the two W's. A variant of this …
Calculations of the atomic and electronic structure for SrTiO3 perovskite thin films
2001
The results of calculations of SrTiO3 (100) surface relaxation and rumpling with two different terminations (SrO and TiO2) are presented and discussed. We have used the ab initio Hartree–Fock (HF) method with electron correlation corrections and the density functional theory (DFT) with different exchange–correlation functionals, including hybrid exchange techniques. All methods agree well on surface energies and on atomic displacements, as well as on the considerable increase of covalency effects near the surface. More detailed experiments on surface rumpling and relaxation are necessary for further testing of theoretical predictions.
Influence of enhancement filters in apical bone loss measurement: A cone-beam computed tomography study
2016
Background The use of cone-beam computed tomography images (CBCT) providing a better assessment of bone injuries, although the sensibility of lesions measurement might be improved by the use of enhancement filters. Objective: This study aimed to analyze the influence of enhancement filters in apical bone loss measurement. Material and Methods Eighteen CBCT cases randomly selected of apical bone loss were evaluated. The analyses were carried out following the evaluation in axial, coronal and sagittal protocols, using enhancement filters as Hard, Normal, and Very Sharp. The variables were statistically analyzed by Friedman and Wilcoxon test, Spearman’s rho, and intraclass correlation coeffici…
The Stabilizing Role of Government Size
2007
This paper presents an analysis of how alternative models of the business cycle can replicate the stylized fact that large governments are associated with less volatile economies. Our analysis shows that adding nominal rigidities and costs of capital adjustment to an otherwise standard RBC model can generate a negative correlation between government size and the volatility of output. However, in the model, we find that the stabilizing effect is only due to a composition effect and it is not present when we look at the volatility of private output. Given that empirically we also observe a negative correlation between government size and the volatility of consumption, we modify the model by i…
Is the Kidscreen-27 a valid measure of health-related quality of life in 10-year-old Norwegian children?
2015
The aim of this study was to investigate the reliability and validity of the Norwegian Kidscreen-27 questionnaire, a measure of generic health-related quality of life, in 10 year-old children. The Kidscreen-27 consists of five domains and was validated in a sample of 56 school children (29 boys). The children completed the questionnaire at three different time points during two consecutive school days. For convergent validity, the study was powered to detect a statistically significant correlation coefficient of 0.4. Cronbach's alpha values ranged from 0.73 to 0.83. Floor effects were all zero and ceiling effects ranged from 1.7% to 23.7%. Intraclass correlation values over time ranged from…
The Relation Between Maternal Locus of Control And Coping Styles of Pediatric Leukemia Patients During Treatment
2020
The present study focuses on the relation between coping strategies of children with leukemia during treatment and locus of control of their mothers. In particular, the study aims to determine whether maternal locus of control can influence sick children’s coping styles, and if this relation can be used to predict maladjustments. The study analyzed a cohort of 60 pediatric leukemia patients undergoing treatment and a group formed by their mothers. The participants were recruited from two Pediatric Onco- Hematology Units in Italy. The Child Behavioral Style Scale (CBSS) was used to assess children’s coping strategies, whereas the Parental Health Locus of Control Scale (PHLCS) was employed to…
Inference for the interclass correlation in familial data using small sample asymptotics
2012
Inference on the parent-offspring correlation coefficient is an important problem in the analysis of familial data, and point estimates and likelihood based inference are available in the literature. In this work, corrections for the signed log-likelihood ratio test statistics are proposed, based on small sample asymptotics, in order to achieve accurate small sample performance. The corrected statistic can be used for hypothesis testing as well as for interval estimation.
Optical nonlinear correlation based on nonuniform subband decomposition
1999
We present a nonlinear correlation to improve the selectivity for optical pattern recognition. The approach is based on morphological correlation which involves a threshold decomposition concept. Hereby, we propose a subband decomposition in the Fourier domain to perform the threshold decomposition operation. We consider two frequency bands that give rise to two separate channels. We apply the morphological correlation to each channel using a localized threshold decomposition. Then, we define a two-channel morphological correlation. The final detection decision is made as a combination of both correlation outputs. The two-channel morphological correlation yields improved discrimination capa…
Correlation and Truth
2013
The concept of correlation is the building block of almost any Bayesian attempt to capture or explicate any interesting aspect of scientific reasoning in terms of probabilities. This paper discusses one particularly simple correlation measure which is highly significant for almost any such attempt within the philosophy of science or epistemology. In particular, it shows how this correlation measure is related to central attempts to capture essential aspects of scientific reasoning such as confirmation, coherence, and the explanatory power of hypotheses. This intimate connection between correlation and scientific reasoning necessitates answering the question of how correlation and truth are …
Scaled factorial moments and split-bin correlation functions. A thermodynamic model comparison
1991
Abstract We compare the scaled factorial moments to the recently proposed split-bin correlation functions, using the thermodynamic model for heavy ion collisions that was recently demonstrated to exhibit power-law growth of the scaled factorial moments as a function of bin size. We find that the split-bin correlation functions are superior for experimental use, as they are intensitive to fictitious correlations due to limited resolving power. In addition, after correction for non-flat single-particle distributions, the split-bin correlation functions provide an unambiguous signal for correlations. As a result, they may provide more powerful evidence for new phenomena like fractal structure …