9,772 research outputs found

    Bayesian Analysis of Simple Random Densities

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    A tractable nonparametric prior over densities is introduced which is closed under sampling and exhibits proper posterior asymptotics.Comment: 19 pages; 6 figure

    Predictive analysis of microarray data

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    Microarray gene expression data are analyzed by means of a Bayesian nonparametric model, with emphasis on prediction of future observables, yielding a method for selection of differentially expressed genes and a classifier

    Structural anomalies for a three dimensional isotropic core-softened potential

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    Using molecular dynamics simulations we investigate the structure of a system of particles interacting through a continuous core-softened interparticle potential. We found for the translational order parameter, t, a local maximum at a density ρtβˆ’max\rho_{t-max} and a local minimum at ρtβˆ’min>ρtβˆ’max\rho_{t-min} > \rho_{t-max}. Between ρtβˆ’max\rho_{t-max} and ρtβˆ’min\rho_{t-min}, the tt parameter anomalously decreases upon pressure. For the orientational order parameter, Q6Q_6, was observed a maximum at a density ρtβˆ’max<ρQmax<ρtβˆ’min\rho_{t-max}< \rho_{Qmax} < \rho_{t-min}. For densities between ρQmax\rho_{Qmax} and ρtβˆ’min\rho_{t-min}, both the translational (t) and orientational (Q6Q_6) order parameters have anomalous behavior. We know that this system also exhibits density and diffusion anomaly. We found that the region in the pressure-temperature phase-diagram of the structural anomaly englobes the region of the diffusion anomaly that is larger than the region limited by the temperature of maximum density. This cascade of anomalies (structural, dynamic and thermodynamic) for our model has the same hierarchy of that one observed for the SPC/E water.Comment: 19 pages, 8 figure
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