34 research outputs found
Gravitational Microlensing by Neutron Stars and Radio Pulsars: Event Rates, Timescale Distributions, and Mass Measurements
We investigate properties of Galactic microlensing events in which a stellar
object is lensed by a neutron star. For an all-sky photometric microlensing
survey, we determine the number of lensing events caused by
potentially-observable radio pulsars to be for
background stellar sources. We expect a few detectable events per
year for the same number of background sources from an astrometric microlensing
survey. We show that such a study could lead to precise measurements of radio
pulsar masses. For instance, if a pulsar distance could be constrained through
radio observations, then its mass would be determined with a precision of
. We also investigate the time-scale distributions for neutron star
events, finding that they are much shorter than had been previously thought.
For photometric events towards the Galactic centre that last days,
around will have a neutron star lens. This fraction drops rapidly for
longer time-scales. Away from the bulge region we find that neutron stars will
contribute of the events that last less than days. These
results are in contrast to earlier work which found that the maximum fraction
of neutron star events would occur on time-scales of hundreds of days.Comment: 10 pages, accepted for publication in ApJ. v2 updated to reflect
change of title in proof stag
Detect Related Bugs from Source Code Using Bug Information
Open source projects often maintain open bug repositories during development
and maintenance, and the reporters often point out straightly or implicitly the
reasons why bugs occur when they submit them. The comments about a bug are very
valuable for developers to locate and fix the bug. Meanwhile, it is very common
in large software for programmers to override or overload some methods
according to the same logic. If one method causes a bug, it is obvious that
other overridden or overloaded methods maybe cause related or similar bugs. In
this paper, we propose and implement a tool Rebug- Detector, which detects
related bugs using bug information and code features. Firstly, it extracts bug
features from bug information in bug repositories; secondly, it locates bug
methods from source code, and then extracts code features of bug methods;
thirdly, it calculates similarities between each overridden or overloaded
method and bug methods; lastly, it determines which method maybe causes
potential related or similar bugs. We evaluate Rebug-Detector on an open source
project: Apache Lucene-Java. Our tool totally detects 61 related bugs,
including 21 real bugs and 10 suspected bugs, and it costs us about 15.5
minutes. The results show that bug features and code features extracted by our
tool are useful to find real bugs in existing projects.Comment: 10 pages, 5 figures, 4 tables conference; 2010 IEEE 34th Annual
Computer Software and Applications Conferenc
3D Interacting Hand Pose Estimation by Hand De-occlusion and Removal
Estimating 3D interacting hand pose from a single RGB image is essential for
understanding human actions. Unlike most previous works that directly predict
the 3D poses of two interacting hands simultaneously, we propose to decompose
the challenging interacting hand pose estimation task and estimate the pose of
each hand separately. In this way, it is straightforward to take advantage of
the latest research progress on the single-hand pose estimation system.
However, hand pose estimation in interacting scenarios is very challenging, due
to (1) severe hand-hand occlusion and (2) ambiguity caused by the homogeneous
appearance of hands. To tackle these two challenges, we propose a novel Hand
De-occlusion and Removal (HDR) framework to perform hand de-occlusion and
distractor removal. We also propose the first large-scale synthetic amodal hand
dataset, termed Amodal InterHand Dataset (AIH), to facilitate model training
and promote the development of the related research. Experiments show that the
proposed method significantly outperforms previous state-of-the-art interacting
hand pose estimation approaches. Codes and data are available at
https://github.com/MengHao666/HDR.Comment: ECCV202
Observation of spin-tensor induced topological phase transitions of triply degenerate points with a trapped ion
Triply degenerate points (TDPs), which correspond to new types of topological
semimetals, can support novel quasiparticles possessing effective integer spins
while preserving Fermi statistics. Here by mapping the momentum space to the
parameter space of a three-level system in a trapped ion, we experimentally
explore the transitions between different types of TDPs driven by
spin-tensor--momentum couplings. We observe the phase transitions between TDPs
with different topological charges by measuring the Berry flux on a loop
surrounding the gap-closing lines, and the jump of the Berry flux gives the
jump of the topological charge (up to a factor) across the transitions.
For the Berry flux measurement, we employ a new method by examining the
geometric rotations of both spin vectors and tensors, which lead to a
generalized solid angle equal to the Berry flux. The controllability of
multi-level ion offers a versatile platform to study high-spin physics and our
work paves the way to explore novel topological phenomena therein.Comment: 9 pages, 10 figure
Recommended from our members
Dual Supramolecular Nanoparticle Vectors Enable CRISPR/Cas9-Mediated Knockin of Retinoschisin 1 Gene-A Potential Nonviral Therapeutic Solution for X-Linked Juvenile Retinoschisis.
The homology-independent targeted integration (HITI) strategy enables effective CRISPR/Cas9-mediated knockin of therapeutic genes in nondividing cells in vivo, promising general therapeutic solutions for treating genetic diseases like X-linked juvenile retinoschisis. Herein, supramolecular nanoparticle (SMNP) vectors are used for codelivery of two DNA plasmids-CRISPR-Cas9 genome-editing system and a therapeutic gene, Retinoschisin 1 (RS1)-enabling clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (CRISPR/Cas9) knockin of the RS1 gene with HITI. Through small-scale combinatorial screenings, two SMNP vectors, with Cas9 and single guide RNA (sgRNA)-plasmid in one and Donor-RS1 and green fluorescent protein (GFP)-plasmid in the other, with optimal delivery performances are identified. These SMNP vectors are then employed for CRISPR/Cas9 knockin of RS1/GFP genes into the mouse Rosa26 safe-harbor site in vitro and in vivo. The in vivo study involves intravitreally injecting the two SMNP vectors into the mouse eyes, followed by repeated ocular imaging by fundus camera and optical coherence tomography, and pathological and molecular analyses of the harvested retina tissues. Mice ocular organs retain their anatomical integrity, a single-copy 3.0-kb RS1/GFP gene is precisely integrated into the Rosa26 site in the retinas, and the integrated RS1/GFP gene is expressed in the retinas, demonstrating CRISPR/Cas9 knockin of RS1/GFP gene