260 research outputs found
Uniform regularity in the low Mach number and inviscid limits for the full Navier-Stokes system in domains with boundaries
Motivated by the studies on the low Mach number limit problem, this
manuscript establishes uniform regularity estimates with respect to the Mach
number for the non-isentropic compressible Navier-Stokes system in smooth
domains with Navier-slip boundary conditions, in the general case of
ill-prepared initial data. The thermal conduction is taken into account and the
large variation of temperature is allowed. Moreover, the obtained regularity
estimates are also uniform in the Reynolds number
P\'eclet number provided
where is a
fixed constant independent of Mach number, Reynolds number and P\'eclet number.
The convergence to the limit system when the Mach number tends to zero is then
justified for an exterior domain outside a smooth compact set in
in the spirit of \cite{MR2106119}.Comment: Comments are welcome
Linear asymptotic stability of small-amplitude periodic waves of the generalized Korteweg--de Vries equations
In this note, we extend the detailed study of the linearized dynamics
obtained for cnoidal waves of the Korteweg--de Vries equation in \cite{JFA-R}
to small-amplitude periodic traveling waves of the generalized Korteweg-de
Vries equations that are not subject to Benjamin--Feir instability. With the
adapted notion of stability, this provides for such waves, global-in-time
bounded stability in any Sobolev space, and asymptotic stability of dispersive
type. When doing so, we actually prove that such results also hold for waves of
arbitrary amplitude satisfying a form of spectral stability designated here as
dispersive spectral stability.Comment: 15 page
Estimating a Large Drive Time Matrix between Zip Codes in the United States: A Differential Sampling Approach
Estimating a massive drive time matrix between locations is a practical but
challenging task. The challenges include availability of reliable road network
(including traffic) data, programming expertise, and access to high-performance
computing resources. This research proposes a method for estimating a
nationwide drive time matrix between ZIP code areas in the U.S.--a geographic
unit at which many national datasets such as health information are compiled
and distributed. The method (1) does not rely on intensive efforts in data
preparation or access to advanced computing resources, (2) uses algorithms of
varying complexity and computational time to estimate drive times of different
trip lengths, and (3) accounts for both interzonal and intrazonal drive times.
The core design samples ZIP code pairs with various intensities according to
trip lengths and derives the drive times via Google Maps API, and the Google
times are then used to adjust and improve some primitive estimates of drive
times with low computational costs. The result provides a valuable resource for
researchers
Suppression of MHC class I surface expression by calreticulin's P-domain in a calreticulin deficient cell line
AbstractCalreticulin (CRT) is an important chaperone protein, comprising an N-domain, P-domain and C-domain. It is involved in the folding and assembly of multi-component protein complexes in the endoplasmic reticulum, and plays a critical role in MHC class I antigen processing and presentation. To dissect the functional role and molecular basis of individual domains of the protein, we have utilized individual domains to rescue impaired protein assembly in a CRT deficient cell line. Unexpectedly, both P-domain fragment and NP domain of CRT not only failed to rescue defective cell surface expression of MHC class I molecules but further inhibited their appearance on the surface of cells. Formation of the TAP-associated peptide-loading complex and trafficking of the few detectable MHC class I molecules were not significantly impaired. Instead, this further suppression of MHC class I molecules on the cell surface appears due to the complex missing antigenic peptides, the third member of fully assembled MHC class I molecules. Therefore the P-domain of calreticulin appears to play a significant role in antigen presentation by MHC class I molecules
Automatic segmentation of meniscus based on MAE self-supervision and point-line weak supervision paradigm
Medical image segmentation based on deep learning is often faced with the
problems of insufficient datasets and long time-consuming labeling. In this
paper, we introduce the self-supervised method MAE(Masked Autoencoders) into
knee joint images to provide a good initial weight for the segmentation model
and improve the adaptability of the model to small datasets. Secondly, we
propose a weakly supervised paradigm for meniscus segmentation based on the
combination of point and line to reduce the time of labeling. Based on the weak
label ,we design a region growing algorithm to generate pseudo-label. Finally
we train the segmentation network based on pseudo-labels with weight transfer
from self-supervision. Sufficient experimental results show that our proposed
method combining self-supervision and weak supervision can almost approach the
performance of purely fully supervised models while greatly reducing the
required labeling time and dataset size.Comment: 8 pages,10 figure
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