234,300 research outputs found
A note of pointwise estimates on Shishkin meshes
We propose the estimates of the discrete Green function for the stream- line
diffusion finite element method (SDFEM) on Shishkin meshes.Comment: 10pages, 1 figur
Some notes on the paper "The mean value of a new arithmetical function"
In reference [2], we used the elementary method to study the mean value prop-
erties of a new arithmetical function, and obtained two mean value formulae for it, but there exist some errors in that paper. The main purpose of this paper is to correct the errors in reference [2], and give two correct conclusions
Shape, orientation and magnitude of the curl quantum flux, the coherence and the statistical correlations in energy transport at nonequilibrium steady state
We provide a quantitative description of the nonequilibriumness based on the
model of coupled oscillators interacting with multiple energy sources. This can
be applied to the study of vibrational energy transport in molecules. The curl
quantum flux quantifying the nonequilibriumness and time-irreversibility is
quantified in the coherent representation and we find the geometric description
of the shape and polarization of the flux which provides the connection between
the microscopic description of quantum nonequilibriumness and the macroscopic
observables, i.e., correlation function. We use the Wilson loop integral to
quantify the magnitude of curl flux, which is shown to be correlated to the
correlation function as well. Coherence contribution is explicitly demonstrated
to be non-trivial and to considerably promote the heat transport quantified by
heat current and efficiency. This comes from the fact that coherence effect is
microscopically reflected by the geometric description of the flux. To uncover
the effect of vibron-phonon coupling between the vibrational modes of molecular
stretching (vibron) and the molecular chain (phonon), we further explore the
influences of localization, which leads to the coherent and incoherent regimes
that are characterised by the current-current correlations.Comment: 21 pages, 6 figure
Compound Poisson Processes, Latent Shrinkage Priors and Bayesian Nonconvex Penalization
In this paper we discuss Bayesian nonconvex penalization for sparse learning
problems. We explore a nonparametric formulation for latent shrinkage
parameters using subordinators which are one-dimensional L\'{e}vy processes. We
particularly study a family of continuous compound Poisson subordinators and a
family of discrete compound Poisson subordinators. We exemplify four specific
subordinators: Gamma, Poisson, negative binomial and squared Bessel
subordinators. The Laplace exponents of the subordinators are Bernstein
functions, so they can be used as sparsity-inducing nonconvex penalty
functions. We exploit these subordinators in regression problems, yielding a
hierarchical model with multiple regularization parameters. We devise ECME
(Expectation/Conditional Maximization Either) algorithms to simultaneously
estimate regression coefficients and regularization parameters. The empirical
evaluation of simulated data shows that our approach is feasible and effective
in high-dimensional data analysis.Comment: Published at http://dx.doi.org/10.1214/14-BA892 in the Bayesian
Analysis (http://projecteuclid.org/euclid.ba) by the International Society of
Bayesian Analysis (http://bayesian.org/
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