Sentence examples for mean attenuation deviation from inspiring English sources
For all cases, including tonal noise represented with relatively few modes, it is shown that statistical characteristics can be described by common probability density functions and conclusions about mean attenuation, deviation from the mean, and cumulative distributions are drawn.
These include probability density functions for transmitted acoustic power and attenuation, expected (mean) attenuation, and standard deviation from the mean.
The signal-to-noise ratio (SNR) was calculated as the mean attenuation value of the ROI/standard deviation of the surrounding oil attenuation value.
The standard deviation of the mean attenuation in the ROI served as an objective measure of noise [34].
Quantitative data such as objective image noise and mean attenuation were analysed by comparing standard deviations, the 95%% confidence interval and statistical differences analysed using repeated analysis of variance (ANOVA) with post-test correction using the Bonferroni method.
The generally accepted lower boundary of normal attenuation muscle is 30 HU (Goodpaster et al. 2000b, Lee et al. 2005), and this was defined as two standard deviations below the mean attenuation value across all pixels of muscles of young healthy persons (Goodpaster et al. 2000b).
The contrast-to-noise ratio (CNR) was calculated as (mean attenuation A – mean attenuation B /image noise (defined as the standard deviation of the surrounding oil).
The mean attenuation coefficient of benign lesions was 5.49 mm−1.
Two independent observers selected regions of interest to measure the mean and standard deviation (SD) of attenuation in the gelatine for all reformatted axial images.
