4,812 research outputs found
Dynamic Kernel Sparsifiers
A geometric graph associated with a set of points and a fixed kernel function
is a
complete graph on such that the weight of edge is
. We present a fully-dynamic data structure that
maintains a spectral sparsifier of a geometric graph under updates that change
the locations of points in one at a time. The update time of our data
structure is with high probability, and the initialization time is
. Under certain assumption, we can provide a fully dynamic spectral
sparsifier with the robostness to adaptive adversary.
We further show that, for the Laplacian matrices of these geometric graphs,
it is possible to maintain random sketches for the results of matrix vector
multiplication and inverse-matrix vector multiplication in time,
under updates that change the locations of points in or change the query
vector by a sparse difference
Data for the gene expression profiling and alternative splicing events during the chondrogenic differentiation of human cartilage endplate-derived stem cells under hypoxia
AbstractThis article contains relevant data of the research article titled Global profiling of the gene expression and alternative splicing events during the hypoxia-regulated chondrogenic differentiation in human cartilage endplate-derived stem cells (Yao et al., 2016) [1]. The data show global profiling of the DEGs (Differentially expressed genes) and AS (Alternative splicing) events during the hypoxia-regulated chondrogenesis of CESCs (human cartilage endplate-derived stem cells) by using Affymetrix Human Transcriptome Array 2.0 (HTA 2.0) system. In addition, the enriched GO (Gene Ontology) functions and signaling pathways are listed. The information presented here includes the information of patients from which the clinical samples are obtained, the list of primers used for validation, the identification, GO and KEGG analysis of DEG and AS events
Power-Law Decay of Standing Waves on the Surface of Topological Insulators
We propose a general theory on the standing waves (quasiparticle interference
pattern) caused by the scattering of surface states off step edges in
topological insulators, in which the extremal points on the constant energy
contour of surface band play the dominant role. Experimentally we image the
interference patterns on both BiTe and BiSe films by measuring
the local density of states using a scanning tunneling microscope. The observed
decay indices of the standing waves agree excellently with the theoretical
prediction: In BiSe, only a single decay index of -3/2 exists; while in
BiTe with strongly warped surface band, it varies from -3/2 to -1/2 and
finally to -1 as the energy increases. The -1/2 decay indicates that the
suppression of backscattering due to time-reversal symmetry does not
necessarily lead to a spatial decay rate faster than that in the conventional
two-dimensional electron system. Our formalism can also explain the
characteristic scattering wave vectors of the standing wave caused by
non-magnetic impurities on BiTe.Comment: 4 pages, 3 figure
Data Processing Pipeline for Pointing Observations of Lunar-based Ultraviolet Telescope
We describe the data processing pipeline developed to reduce the pointing
observation data of Lunar-based Ultraviolet Telescope (LUT), which belongs to
the Chang'e-3 mission of the Chinese Lunar Exploration Program. The pointing
observation program of LUT is dedicated to monitor variable objects in a
near-ultraviolet (245-345 nm) band. LUT works in lunar daytime for sufficient
power supply, so some special data processing strategies have been developed
for the pipeline. The procedures of the pipeline include stray light removing,
astrometry, flat fielding employing superflat technique, source extraction and
cosmic rays rejection, aperture and PSF photometry, aperture correction, and
catalogues archiving, etc. It has been intensively tested and works smoothly
with observation data. The photometric accuracy is typically ~0.02 mag for LUT
10 mag stars (30 s exposure), with errors come from background noises,
residuals of stray light removing, and flat fielding related errors. The
accuracy degrades to be ~0.2 mag for stars of 13.5 mag which is the 5{\sigma}
detection limit of LUT.Comment: 10 pages, 7 figures, 4 tables. Minor changes and some expounding
words added. Version accepted for publication in Astrophysics and Space
Science (Ap&SS
Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3
Searching for superconducting materials with high transition temperature (TC)
is one of the most exciting and challenging fields in physics and materials
science. Although superconductivity has been discovered for more than 100
years, the copper oxides are so far the only materials with TC above 77 K, the
liquid nitrogen boiling point. Here we report an interface engineering method
for dramatically raising the TC of superconducting films. We find that one
unit-cell (UC) thick films of FeSe grown on SrTiO3 (STO) substrates by
molecular beam epitaxy (MBE) show signatures of superconducting transition
above 50 K by transport measurement. A superconducting gap as large as 20 meV
of the 1 UC films observed by scanning tunneling microcopy (STM) suggests that
the superconductivity could occur above 77 K. The occurrence of
superconductivity is further supported by the presence of superconducting
vortices under magnetic field. Our work not only demonstrates a powerful way
for finding new superconductors and for raising TC, but also provides a
well-defined platform for systematic study of the mechanism of unconventional
superconductivity by using different superconducting materials and substrates
Universal critical properties of the Eulerian bond-cubic model
We investigate the Eulerian bond-cubic model on the square lattice by means
of Monte Carlo simulations, using an efficient cluster algorithm and a
finite-size scaling analysis. The critical points and four critical exponents
of the model are determined for several values of . Two of the exponents are
fractal dimensions, which are obtained numerically for the first time. Our
results are consistent with the Coulomb gas predictions for the critical O()
branch for and the results obtained by previous transfer matrix
calculations. For , we find that the thermal exponent, the magnetic
exponent and the fractal dimension of the largest critical Eulerian bond
component are different from those of the critical O(2) loop model. These
results confirm that the cubic anisotropy is marginal at but irrelevant
for
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