27,483 research outputs found
Double occupancies in confined attractive fermions on optical lattices
We perform a numerical study of a one-dimensional Fermion-Hubbard model in
harmonic traps within the Thomas-Fermi approximation based on the exact
Bethe-ansatz solution. The phase diagram is shown for the systems of
attractive interactions ( is the characteristic density and the
interaction strength scaled in units of the hopping parameter.). We study the
double occupancy, the local central density and their derivatives. Their roles
are discussed in details in detecting the composite phases induced by the
trapping potential.Comment: 4 pages, 4 figures, submitte
RIDDLE: Race and ethnicity Imputation from Disease history with Deep LEarning
Anonymized electronic medical records are an increasingly popular source of
research data. However, these datasets often lack race and ethnicity
information. This creates problems for researchers modeling human disease, as
race and ethnicity are powerful confounders for many health exposures and
treatment outcomes; race and ethnicity are closely linked to
population-specific genetic variation. We showed that deep neural networks
generate more accurate estimates for missing racial and ethnic information than
competing methods (e.g., logistic regression, random forest). RIDDLE yielded
significantly better classification performance across all metrics that were
considered: accuracy, cross-entropy loss (error), and area under the curve for
receiver operating characteristic plots (all ). We made specific
efforts to interpret the trained neural network models to identify, quantify,
and visualize medical features which are predictive of race and ethnicity. We
used these characterizations of informative features to perform a systematic
comparison of differential disease patterns by race and ethnicity. The fact
that clinical histories are informative for imputing race and ethnicity could
reflect (1) a skewed distribution of blue- and white-collar professions across
racial and ethnic groups, (2) uneven accessibility and subjective importance of
prophylactic health, (3) possible variation in lifestyle, such as dietary
habits, and (4) differences in background genetic variation which predispose to
diseases
Determination of heat transfer coefficient for hot stamping process
© 2015 The Authors.The selection of the heat transfer coefficient is one of the most important factors that determine the reliability of FE simulation results of a hot stamping process, in which the formed component is held within cold dies until fully quenched. The quenching process could take up to 10. seconds. In order to maximise the production rate, the optimised quenching parameters should be identified to achieve the highest possible quenching rate and to reduce the quenching time. For this purpose, a novel-testing rig for the Gleeble 3800 thermo- mechanical simulator was designed and manufactured, with an advanced control system for temperature and contact pressure. The effect of contact pressure on the heat transfer coefficient was studied. The findings of this research will provide useful guidelines for the selection of the heat transfer coefficient in simulations of hot stamping processes and useful information for the design of hot stamping processes
Three-Body Recombination near a Narrow Feshbach Resonance in 6 Li
We experimentally measure and theoretically analyze the three-atom recombination rate,
L3, around a narrow s-wave magnetic Feshbach resonance of 6Li−6Li at 543.3 G. By examining both the magnetic field dependence and, especially, the temperature dependence of L3 over a wide range of temperatures from a few μK to above 200 μK, we show that three-atom recombination through a narrow resonance follows a universal behavior determined by the long-range van der Waals potential and can be described by a set of rate equations in which three-body recombination proceeds via successive pairwise interactions. We expect the underlying physical picture to be applicable not only to narrow
s wave resonances, but also to resonances in nonzero partial waves, and not only at ultracold temperatures, but also at much higher temperatures
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