2,113 research outputs found
Competition of exchange and crystal field interactions in cerium monopnictides and monochalcogenides
Strongly Correlated Cerium Systems: Non-Kondo Mechanism for Moment Collapse
We present an ab initio based method which gives clear insight into the
interplay between the hybridization, the coulomb exchange, and the
crystal-field interactions, as the degree of 4f localization is varied across a
series of strongly correlated cerium systems. The results for the ordered
magnetic moments, magnetic structure, and ordering temperatures are in
excellent agreement with experiment, including the occurence of a moment
collapse of non-Kondo origin. In contrast, standard ab initio density
functional calculations fail to predict, even qualitatively, the trend of the
unusual magentic properties.Comment: A shorter version of this has been submitted to PR
Predicting subjective refraction with dynamic retinal image quality analysis
The aim of this work is to evaluate the performance of a novel algorithm that combines dynamic
wavefront aberrometry data and descriptors of the retinal image quality from objective autorefractor
measurements to predict subjective refraction. We conducted a retrospective study of the prediction
accuracy and precision of the novel algorithm compared to standard search-based retinal image
quality optimization algorithms. Dynamic measurements from 34 adult patients were taken with a
handheld wavefront autorefractor and static data was obtained with a high-end desktop wavefront
aberrometer. The search-based algorithms did not signifcantly improve the results of the desktop
system, while the dynamic approach was able to simultaneously reduce the standard deviation (up
to a 15% for reduction of spherical equivalent power) and the mean bias error of the predictions (up
to 80% reduction of spherical equivalent power) for the handheld aberrometer. These results suggest
that dynamic retinal image analysis can substantially improve the accuracy and precision of the
portable wavefront autorefractor relative to subjective refraction.The authors thanks to Dr. David Friedman (Wilmer Eye Institute, Johns Hopkins University School of Medicine)
and his team for their help with study defnition and data acquisition. Eduardo Lage is funded by the Ramon y
Cajal program from the Spanish Ministry of Economy, Industry and Competitivity (RYC-2016-21125). Carlos
S. Hernandez, and Andrea Gil are funded by the Madrid Regional Government through IND2019/TIC-17116
and IND2020/TIC-17340 grants. Research relating to the autorefractor reported in this publication was partially
support by the National Institute of Biomedical Imaging & Bioengineering and National Eye Institute of the
National Institutes of Health under Award Numbers R43EB024299 and R44EY025452, respectivel
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