Sentences with word «covariance»

We analyzed data using the LISREL 8 analysis of covariance structure approach to path analysis and maximum likelihood estimates.175

Part of this discussion will deal with the estimation of large covariance matrices, which is a key issue in D&A.

Statistical analyses (repeated measures analysis of covariance with intent - to - treat) revealed statistically and clinically significant reduction in PTSD symptoms (p < 0.0005, Cohen's d = 0.85) as well as depression (p < 0.0005, Cohen's d = 0.70) for the group receiving HT+GI vs. TAU.

Field intercomparison of four methane gas analyzers suitable for eddy covariance flux measurements

[jounal] Hu, L. J. / 1999 / Cutoff criteria for fit indexes in covariance structure analysis: Conventional criteria versus new alternative / Structural Equation Modeling 6: 1 ~ 55

After excluding stocks with fewer than three years of immediately past data, the researchers used up to five years of monthly returns to estimate covariance matrices and optimize portfolios.

Analysis of longitudinal studies with missing data using covariance structure modeling with full - information maximum likelihood

[Response: The AWS records useful because they provide a totally independent estimate of the spatial covariance pattern in the temperature field (which we primarily get from satellites).

The error covariance matrix at level 1 (among the different measures of child problems) was modeled as unstructured.

Measurements of GPP by eddy covariance methods is auto - correlated with other components of the carbon cycle and is restricted to specific locations.

Celis et al., 2017 combined six years of eddy covariance flux tower data and soil respiration chambers and found that a moist tundra site was a source of carbon to the atmosphere, but much of the net source arises from the slow, but continuous emissions in winter.

Loadings for the slope factors were constrained to the estimates from the unconditional models and covariances across the growth models were freely estimated.

The tower is part of the AmeriFlux network, a consortium of scientists using a network to work with the eddy covariance technique, measuring fluxes of CO2 and CH4 at multiple sites across the Americas.

From an unstructured covariance matrix for the intercept and race effects, their correlation coefficient was calculated as

Factor analyses of autistic traits in clinical ASD and community samples, using a variety of ASD measurement tools, generally indicate that multiple factors account for the observed covariance structure of ASD symptoms and traits (Happé and Ronald 2008; Mandy and Skuse 2008).

A negative covariance means returns move inversely.

Estimating background error covariance parameters and assessing their impact in the OSTIA system Read more»

In this specific site, the researchers are measuring the exchange of CO2 and CH4 between the ecosystem and the atmosphere using the first eddy covariance tower established in the state of Delaware since 2015.

Final models control for dependence over time assuming autoregressive covariance structure that provided the best fit of the models.

Linear regressions and analyses of covariance adjusted for various background variables were conducted.

Single - headed arrows are path coefficients and curved, bidirectional arrows represent covariances.

They chose principal component analysis (PCA) to overcome the estimation errors inherent in sample covariance matrices.

For any given level of correlation with the predictand, a high - variance predictor variable will have a higher covariance with it than a low - variance one.

These results indicate that cortical regions within rsFC - defined systems exhibit similar thinning patterns across the lifespan, and that structural covariance of cortical thinning may delineate local cortical distinctions.

You shouldn't expect much covariance.

A positive covariance means that asset returns move together.

Non-significant tracts and region covariances were estimated but are omitted for clarity.

In practise the estimated covariance function of the joint output / input signal obtained by a closed loop experiment will [b] never [/ b] have the structural properties associated with the feedback system.

«I should have computed the historical covariances of the asset classes and drawn an efficient frontier,» Markowitz once said.

Whitening involving transforming the discrepancies, using an estimate of the inverse spatio - temporal natural variability covariance matrix, so that they would, in a perfect world, be independent standardised normal random variables.