3,867 research outputs found
Lifshitz holographic superconductor in Horava-Lifshitz gravity
We study the holographic phase transition of superconductor dual to a
Lifshitz black brane probed by an anisotropic scalar field in the probe limit
in Ho\u{r}ava-Lifshitz gravity. With the use of numerical and analytical
method, we investigate how the critical temperature of the condensation is
affected by the Lifshitz exponent , correction term in the action
as well as the dimensions of the gravity. We also numerically explore the
condensation of the dual operator and optical conductivity of the holographic
system. Various interesting properties of the holographic condensation affected
by the parameters of model are discussed
Ferroelectricity of Ice Nanotubes inside Carbon Nanotubes
We report that ice nanotubes with odd number of side faces inside carbon
nanotubes exhibit spontaneous electric polarization along its axes direction by
using molecular dynamics simulations. The mechanism of this nanoscale
quasi-one-dimensional ferroelectricity is due to low dimensional confinement
and the orientational order of hydrogen bonds. These ferroelectric fiber
structural materials are different from traditional perovskite structural bulk
materials.Comment: 4 pages and 4 figure
RotationDrag: Point-based Image Editing with Rotated Diffusion Features
A precise and user-friendly manipulation of image content while preserving
image fidelity has always been crucial to the field of image editing. Thanks to
the power of generative models, recent point-based image editing methods allow
users to interactively change the image content with high generalizability by
clicking several control points. But the above mentioned editing process is
usually based on the assumption that features stay constant in the motion
supervision step from initial to target points. In this work, we conduct a
comprehensive investigation in the feature space of diffusion models, and find
that features change acutely under in-plane rotation. Based on this, we propose
a novel approach named RotationDrag, which significantly improves point-based
image editing performance when users intend to in-plane rotate the image
content. Our method tracks handle points more precisely by utilizing the
feature map of the rotated images, thus ensuring precise optimization and high
image fidelity. Furthermore, we build a in-plane rotation focused benchmark
called RotateBench, the first benchmark to evaluate the performance of
point-based image editing method under in-plane rotation scenario on both real
images and generated images. A thorough user study demonstrates the superior
capability in accomplishing in-plane rotation that users intend to achieve,
comparing the DragDiffusion baseline and other existing diffusion-based
methods. See the project page https://github.com/Tony-Lowe/RotationDrag for
code and experiment results.Comment: Code is released at https://github.com/Tony-Lowe/RotationDra
On Shapley Value in Data Assemblage Under Independent Utility
In many applications, an organization may want to acquire data from many data
owners. Data marketplaces allow data owners to produce data assemblage needed
by data buyers through coalition. To encourage coalitions to produce data, it
is critical to allocate revenue to data owners in a fair manner according to
their contributions. Although in literature Shapley fairness and alternatives
have been well explored to facilitate revenue allocation in data assemblage,
computing exact Shapley value for many data owners and large assembled data
sets through coalition remains challenging due to the combinatoric nature of
Shapley value. In this paper, we explore the decomposability of utility in data
assemblage by formulating the independent utility assumption. We argue that
independent utility enjoys many applications. Moreover, we identify interesting
properties of independent utility and develop fast computation techniques for
exact Shapley value under independent utility. Our experimental results on a
series of benchmark data sets show that our new approach not only guarantees
the exactness of Shapley value, but also achieves faster computation by orders
of magnitudes.Comment: Accepted by VLDB 202
Three-dimensional numerical study of flow characteristic and membrane fouling evolution in an enzymatic membrane reactor
In order to enhance the understanding of membrane fouling mechanism, the
hydrodynamics of granular flow in a stirred enzymatic membrane reactor was
numerically investigated in the present study. A three-dimensional Euler-Euler
model, coupled with k-e mixture turbulence model and drag function for
interphase momentum exchange, was applied to simulate the two-phase
(fluid-solid) turbulent flow. Numerical simulations of single- or two-phase
turbulent flow under various stirring speed were implemented. The numerical
results coincide very well with some published experimental data. Results for
the distributions of velocity, shear stress and turbulent kinetic energy were
provided. Our results show that the increase of stirring speed could not only
enlarge the circulation loops in the reactor, but it can also increase the
shear stress on the membrane surface and accelerate the mixing process of
granular materials. The time evolution of volumetric function of granular
materials on the membrane surface has qualitatively explained the evolution of
membrane fouling.Comment: 10 panges, 8 figure
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