2,504 research outputs found
Convergence of Phase-Field Free Energy and Boundary Force for Molecular Solvation
We study a phase-field variational model for the solvaiton of charged
molecules with an implicit solvent. The solvation free-energy functional of all
phase fields consists of the surface energy, solute excluded volume and
solute-solvent van der Waals dispersion energy, and electrostatic free energy.
The surface energy is defined by the van der Waals--Cahn--Hilliard functional
with squared gradient and a double-well potential. The electrostatic part of
free energy is defined through the electrostatic potential governed by the
Poisson--Boltzmann equation in which the dielectric coefficient is defined
through the underlying phase field. We prove the continuity of the
electrostatics---its potential, free energy, and dielectric boundary
force---with respect to the perturbation of dielectric boundary. We also prove
the -convergence of the phase-field free-energy functionals to their
sharp-interface limit, and the equivalence of the convergence of total free
energies to that of all individual parts of free energy. We finally prove the
convergence of phase-field forces to their sharp-interface limit. Such forces
are defined as the negative first variations of the free-energy functional; and
arise from stress tensors. In particular, we obtain the force convergence for
the van der Waals--Cahn--Hilliard functionals with minimal assumptions.Comment: 40 page
Skeleton based action recognition using translation-scale invariant image mapping and multi-scale deep cnn
This paper presents an image classification based approach for skeleton-based
video action recognition problem. Firstly, A dataset independent
translation-scale invariant image mapping method is proposed, which transformes
the skeleton videos to colour images, named skeleton-images. Secondly, A
multi-scale deep convolutional neural network (CNN) architecture is proposed
which could be built and fine-tuned on the powerful pre-trained CNNs, e.g.,
AlexNet, VGGNet, ResNet etal.. Even though the skeleton-images are very
different from natural images, the fine-tune strategy still works well. At
last, we prove that our method could also work well on 2D skeleton video data.
We achieve the state-of-the-art results on the popular benchmard datasets e.g.
NTU RGB+D, UTD-MHAD, MSRC-12, and G3D. Especially on the largest and challenge
NTU RGB+D, UTD-MHAD, and MSRC-12 dataset, our method outperforms other methods
by a large margion, which proves the efficacy of the proposed method
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