767 research outputs found
Multi-Mobile Robot Localization and Navigation based on Visible Light Positioning
We demonstrated multi-mobile robot navigation based on Visible Light
Positioning(VLP) localization. From our experiment, the VLP can accurately
locate robots' positions in navigation
ROME: Testing Image Captioning Systems via Recursive Object Melting
Image captioning (IC) systems aim to generate a text description of the
salient objects in an image. In recent years, IC systems have been increasingly
integrated into our daily lives, such as assistance for visually-impaired
people and description generation in Microsoft Powerpoint. However, even the
cutting-edge IC systems (e.g., Microsoft Azure Cognitive Services) and
algorithms (e.g., OFA) could produce erroneous captions, leading to incorrect
captioning of important objects, misunderstanding, and threats to personal
safety. The existing testing approaches either fail to handle the complex form
of IC system output (i.e., sentences in natural language) or generate unnatural
images as test cases. To address these problems, we introduce Recursive Object
MElting (Rome), a novel metamorphic testing approach for validating IC systems.
Different from existing approaches that generate test cases by inserting
objects, which easily make the generated images unnatural, Rome melts (i.e.,
remove and inpaint) objects. Rome assumes that the object set in the caption of
an image includes the object set in the caption of a generated image after
object melting. Given an image, Rome can recursively remove its objects to
generate different pairs of images. We use Rome to test one widely-adopted
image captioning API and four state-of-the-art (SOTA) algorithms. The results
show that the test cases generated by Rome look much more natural than the SOTA
IC testing approach and they achieve comparable naturalness to the original
images. Meanwhile, by generating test pairs using 226 seed images, Rome reports
a total of 9,121 erroneous issues with high precision (86.47%-92.17%). In
addition, we further utilize the test cases generated by Rome to retrain the
Oscar, which improves its performance across multiple evaluation metrics.Comment: Accepted by ISSTA 202
Spectrum Sharing between UAV-based Wireless Mesh Networks and Ground Networks
The unmanned aerial vehicle (UAV)-based wireless mesh networks can
economically provide wireless services for the areas with disasters. However,
the capacity of air-to-air communications is limited due to the multi-hop
transmissions. In this paper, the spectrum sharing between UAV-based wireless
mesh networks and ground networks is studied to improve the capacity of the UAV
networks. Considering the distribution of UAVs as a three-dimensional (3D)
homogeneous Poisson point process (PPP) within a vertical range, the stochastic
geometry is applied to analyze the impact of the height of UAVs, the transmit
power of UAVs, the density of UAVs and the vertical range, etc., on the
coverage probability of ground network user and UAV network user, respectively.
The optimal height of UAVs is numerically achieved in maximizing the capacity
of UAV networks with the constraint of the coverage probability of ground
network user. This paper provides a basic guideline for the deployment of
UAV-based wireless mesh networks.Comment: 6 pages, 6 figure
Non-Fluorinated Proton Exchange Membranes Based on Melt Extruded SEBS/HDPE Blends
Peer reviewed: YesNRC publication: Ye
The influence of fractionation of REE-enriched minerals on the zircon partition coefficients
Zircon is widely used to simulate melt generation, migration and evolution within the crust and mantle. The achievable performance of melt modelling generally depends on the availability of reliable trace element partition coefficients (D). However, a large range of DREE values for zircon from natural samples and experimental studies has been reported, with values spanning up to 3 orders of magnitude. Unfortunately, a gap of knowledge on this variability is evident. In this study we model the crystallization processes of common REE-bearing minerals from granitic melts and show that the measured zircon DREE would be elevated if there is crystallization of REE-enriched minerals subsequent to zircon. Nevertheless, compared to zircon DREE values measured from experimental studies, this mechanism appears to have a less significant influence on those from natural granite samples since the quantity of crystallized REE-enriched minerals is very low in natural magmatic systems and/or most of them crystallize prior to zircon. Combined with recently published studies, this work supports that analysis of natural zircon/host groundmass pairs provides more robust DREE values applicable to natural systems than those measured from experimental studies, which can be used to constrain the provenance of detrital zircons.This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. It is available as an open access article under a Creative Commons Licence https://creativecommons.org/licenses/by-nc-nd/4.0/
N6-methyladenosine RNA modification promotes viral genomic RNA stability and infection
Molecular manipulation of susceptibility (S) genes that are antipodes to resistance (R) genes has been adopted as an alternative strategy for controlling crop diseases. Here, we show the S gene encoding Triticum aestivum m(6)A methyltransferase B (TaMTB) is identified by a genome-wide association study and subsequently shown to be a positive regulator for wheat yellow mosaic virus (WYMV) infection. TaMTB is localized in the nucleus, is translocated into the cytoplasmic aggregates by binding to WYMV NIb to upregulate the m(6)A level of WYMV RNA1 and stabilize the viral RNA, thus promoting viral infection. A natural mutant allele TaMTB-SNP176C is found to confer an enhanced susceptibility to WYMV infection through genetic variation analysis on 243 wheat varieties. Our discovery highlights this allele can be a useful target for the molecular wheat breeding in the future
Higher-order multipole amplitude measurement in
Using events collected with the BESIII detector at
the BEPCII storage ring, the higher-order multipole amplitudes in the radiative
transition are measured.
A fit to the production and decay angular distributions yields
and , where the first
errors are statistical and the second systematic. Here denotes the
normalized magnetic quadrupole amplitude and the normalized electric
octupole amplitude. This measurement shows evidence for the existence of the
signal with statistical significance and is consistent with
the charm quark having no anomalous magnetic moment.Comment: 14 pages, 4 figure
Precision measurement of the branching fractions of J/psi -> pi+pi-pi0 and psi' -> pi+pi-pi0
We study the decays of the J/psi and psi' mesons to pi+pi-pi0 using data
samples at both resonances collected with the BES III detector in 2009. We
measure the corresponding branching fractions with unprecedented precision and
provide mass spectra and Dalitz plots. The branching fraction for J/psi ->
pi+pi-pi0 is determined to be (2.137 +- 0.004 (stat.) +0.058-0.056 (syst.)
+0.027-0.026 (norm.))*10-2, and the branching fraction for psi' -> pi+pi-pi0 is
measured as (2.14 +- 0.03 (stat.) +0.08-0.07 (syst.) +0.09-0.08 (norm.))*10-4.
The J/psi decay is found to be dominated by an intermediate rho(770) state,
whereas the psi' decay is dominated by di-pion masses around 2.2 GeV/c2,
leading to strikingly different Dalitz distributions.Comment: 15 pages, 2 figure
Study of and
The decays and have been
investigated with a sample of 225.2 million events collected with the
BESIII detector at the BEPCII collider. The branching fractions are
determined to be and . Distributions of the angle
between the proton or anti-neutron and the beam direction are well
described by the form , and we find
for and
for . Our branching-fraction
results suggest a large phase angle between the strong and electromagnetic
amplitudes describing the decay.Comment: 16 pages, 13 figures, the 2nd version, submitted to PR
- …