59 research outputs found
Target-Driven Structured Transformer Planner for Vision-Language Navigation
Vision-language navigation is the task of directing an embodied agent to
navigate in 3D scenes with natural language instructions. For the agent,
inferring the long-term navigation target from visual-linguistic clues is
crucial for reliable path planning, which, however, has rarely been studied
before in literature. In this article, we propose a Target-Driven Structured
Transformer Planner (TD-STP) for long-horizon goal-guided and room layout-aware
navigation. Specifically, we devise an Imaginary Scene Tokenization mechanism
for explicit estimation of the long-term target (even located in unexplored
environments). In addition, we design a Structured Transformer Planner which
elegantly incorporates the explored room layout into a neural attention
architecture for structured and global planning. Experimental results
demonstrate that our TD-STP substantially improves previous best methods'
success rate by 2% and 5% on the test set of R2R and REVERIE benchmarks,
respectively. Our code is available at https://github.com/YushengZhao/TD-STP
Spectrum-Guided Adversarial Disparity Learning
It has been a significant challenge to portray intraclass disparity precisely
in the area of activity recognition, as it requires a robust representation of
the correlation between subject-specific variation for each activity class. In
this work, we propose a novel end-to-end knowledge directed adversarial
learning framework, which portrays the class-conditioned intraclass disparity
using two competitive encoding distributions and learns the purified latent
codes by denoising learned disparity. Furthermore, the domain knowledge is
incorporated in an unsupervised manner to guide the optimization and further
boosts the performance. The experiments on four HAR benchmark datasets
demonstrate the robustness and generalization of our proposed methods over a
set of state-of-the-art. We further prove the effectiveness of automatic domain
knowledge incorporation in performance enhancement
Observation of multiple superconducting gaps in Fe1+yTe1-xSex via a nano-scale approach to point-contact spectroscopy
We report a distinct experimental approach to point-contact Andreev
reflection spectroscopy with diagnostic capability via a unique design of
nano-scale normal metal/superconductor devices with excellent thermo-mechanical
stability, and have employed this method to unveil the existence of two
superconducting energy gaps in iron chalcogenide Fe1+yTe1-xSex which is crucial
for understanding its pairing mechanism. This work opens up new opportunities
to study gap structures in superconductors and elemental excitations in solids.Comment: 18 pages (5 figures) plus supplementary materials (5 pages). J.
Phys.: Cond. Matter, in pres
The energy spectrum of all-particle cosmic rays around the knee region observed with the Tibet-III air-shower array
We have already reported the first result on the all-particle spectrum around
the knee region based on data from 2000 November to 2001 October observed by
the Tibet-III air-shower array. In this paper, we present an updated result
using data set collected in the period from 2000 November through 2004 October
in a wide range over 3 decades between eV and eV, in which
the position of the knee is clearly seen at around 4 PeV. The spectral index is
-2.68 0.02(stat.) below 1PeV, while it is -3.12 0.01(stat.) above 4
PeV in the case of QGSJET+HD model, and various systematic errors are under
study now.Comment: 12 pages, 7 figures, accepted by Advances in space researc
Moon Shadow by Cosmic Rays under the Influence of Geomagnetic Field and Search for Antiprotons at Multi-TeV Energies
We have observed the shadowing of galactic cosmic ray flux in the direction
of the moon, the so-called moon shadow, using the Tibet-III air shower array
operating at Yangbajing (4300 m a.s.l.) in Tibet since 1999. Almost all cosmic
rays are positively charged; for that reason, they are bent by the geomagnetic
field, thereby shifting the moon shadow westward. The cosmic rays will also
produce an additional shadow in the eastward direction of the moon if cosmic
rays contain negatively charged particles, such as antiprotons, with some
fraction. We selected 1.5 x10^{10} air shower events with energy beyond about 3
TeV from the dataset observed by the Tibet-III air shower array and detected
the moon shadow at level. The center of the moon was detected
in the direction away from the apparent center of the moon by 0.23 to
the west. Based on these data and a full Monte Carlo simulation, we searched
for the existence of the shadow produced by antiprotons at the multi-TeV energy
region. No evidence of the existence of antiprotons was found in this energy
region. We obtained the 90% confidence level upper limit of the flux ratio of
antiprotons to protons as 7% at multi-TeV energies.Comment: 13pages,4figures; Accepted for publication in Astroparticle Physic
The all-particle spectrum of primary cosmic rays in the wide energy range from 10^14 eV to 10^17 eV observed with the Tibet-III air-shower array
We present an updated all-particle energy spectrum of primary cosmic rays in
a wide range from 10^14 eV to 10^17 eV using 5.5 times 10^7 events collected in
the period from 2000 November through 2004 October by the Tibet-III air-shower
array located at 4300 m above sea level (atmospheric depth of 606 g/cm^2). The
size spectrum exhibits a sharp knee at a corresponding primary energy around 4
PeV. This work uses increased statistics and new simulation calculations for
the analysis. We performed extensive Monte Carlo calculations and discuss the
model dependences involved in the final result assuming interaction models of
QGSJET01c and SIBYLL2.1 and primary composition models of heavy dominant (HD)
and proton dominant (PD) ones. Pure proton and pure iron primary models are
also examined as extreme cases. The detector simulation was also made to
improve the accuracy of determining the size of the air showers and the energy
of the primary particle. We confirmed that the all-particle energy spectra
obtained under various plausible model parameters are not significantly
different from each other as expected from the characteristics of the
experiment at the high altitude, where the air showers of the primary energy
around the knee reaches near maximum development and their features are
dominated by electromagnetic components leading to the weak dependence on the
interaction model or the primary mass. This is the highest-statistical and the
best systematics-controlled measurement covering the widest energy range around
the knee energy region.Comment: 19 pages, 20 figures, accepted by Ap
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