714 research outputs found
EgoThink: Evaluating First-Person Perspective Thinking Capability of Vision-Language Models
Vision-language models (VLMs) have recently shown promising results in
traditional downstream tasks. Evaluation studies have emerged to assess their
abilities, with the majority focusing on the third-person perspective, and only
a few addressing specific tasks from the first-person perspective. However, the
capability of VLMs to "think" from a first-person perspective, a crucial
attribute for advancing autonomous agents and robotics, remains largely
unexplored. To bridge this research gap, we introduce EgoThink, a novel visual
question-answering benchmark that encompasses six core capabilities with twelve
detailed dimensions. The benchmark is constructed using selected clips from
egocentric videos, with manually annotated question-answer pairs containing
first-person information. To comprehensively assess VLMs, we evaluate eighteen
popular VLMs on EgoThink. Moreover, given the open-ended format of the answers,
we use GPT-4 as the automatic judge to compute single-answer grading.
Experimental results indicate that although GPT-4V leads in numerous
dimensions, all evaluated VLMs still possess considerable potential for
improvement in first-person perspective tasks. Meanwhile, enlarging the number
of trainable parameters has the most significant impact on model performance on
EgoThink. In conclusion, EgoThink serves as a valuable addition to existing
evaluation benchmarks for VLMs, providing an indispensable resource for future
research in the realm of embodied artificial intelligence and robotics
Ion Transport through Short Nanopores Modulated by Charged Exterior Surfaces
Short nanopores find extensive applications capitalizing on their high
throughput and detection resolution. Ionic behaviors through long nanopores are
mainly determined by charged inner-pore walls. When pore lengths decrease to
sub-200 nm, charged exterior surfaces provide considerable modulation to ion
current. We find that the charge status of inner-pore walls affects the
modulation of ion current from charged exterior surfaces. For 50-nm-long
nanopores with neutral inner-pore walls, charged exterior surfaces on the
voltage (surfaceV) and ground (surfaceG) sides enhance and inhibit ion
transport by forming ion enrichment and depletion zones inside nanopores,
respectively. For nanopores with both charged inner-pore and exterior surfaces,
continuous electric double layers enhance ion transport through nanopores
significantly. The charged surfaceV results in higher ion current by
simultaneously weakening ion depletion at pore entrances and enhancing the
intra-pore ion enrichment. The charged surfaceG expedites the exit of ions from
nanopores, resulting in a decrease in ion enrichment at pore exits. Through
adjustment in the width of charged-ring regions near pore boundaries, the
effective charged width of the charged exterior is explored at ~20nm. Our
results may provide a theoretical guide for further optimizing the performance
of nanopore-based applications, like seawater desalination, biosensing, and
osmotic energy conversion.Comment: 18 pages, 5 figure
Air Traffic Scenario Evaluation Based on Metric Learning
Air traffic scenario evaluation can support the optimisation of traffic flow and airspace configuration to improve the safety of air traffic control. Since the air traffic scenario is influenced by the interaction of multiple factors, and real labelled data are lacking, the feature index selection and scenario evaluation are challenging endeavours. In this study, indicators were selected from three dimensions: airspace structure, traffic characteristics and meteorological conditions. The evaluation indicators were quantitatively screened according to information importance and overlap. Utilising the flow control and traffic flow information, the authors defined the free and saturated states of the state interval and developed a metric-based learning method to calibrate the state samples. A multilayer perceptron regression model was employed to establish the mapping relationship between the feature indicators and air traffic scenario. The evaluation accuracy of the sample set from three sectors in Shanghai exceeded 80%, which verified the effectiveness of the scenario evaluation model. This contribution holds practical significance in enhancing the safety of airspace operations
Blocking Ion Migration Stabilizes the High Thermoelectric Performance in Cu2Se Composites
The applications of mixed ionic–electronic conductors are limited due to phase instability under a high direct current and large temperature difference. Here, it is shown that Cu2Se is stabilized through regulating the behaviors of Cu+ ions and electrons in a Schottky heterojunction between the Cu2Se host matrix and in‐situ‐formed BiCuSeO nanoparticles. The accumulation of Cu+ ions via an ionic capacitive effect at the Schottky junction under the direct current modifies the space‐charge distribution in the electric double layer, which blocks the long‐range migration of Cu+ and produces a drastic reduction of Cu+ ion migration by nearly two orders of magnitude. Moreover, this heterojunction impedes electrons transferring from BiCuSeO to Cu2Se, obstructing the reduction reaction of Cu+ into Cu metal at the interface and hence stabilizes the β‐Cu2Se phase. Furthermore, incorporation of BiCuSeO in Cu2Se optimizes the carrier concentration and intensifies phonon scattering, contributing to the peak figure of merit ZT value of ≈2.7 at 973 K and high average ZT value of ≈1.5 between 400 and 973 K for the Cu2Se/BiCuSeO composites. This discovery provides a new avenue for stabilizing mixed ionic–electronic conduction thermoelectrics, and gives fresh insights into controlling ion migration in these ionic‐transport‐dominated materials.The space‐charge region between Cu2Se host matrix and in‐situ‐formed BiCuSeO under a direct current causes drastic suppression of the Cu+ ion migration in such composites and obstructs the reduction reaction of Cu+ into Cu metal. This, together with the effective regulation of carrier concentration as well as enhanced interfacial phonon scattering, greatly stabilizes the improved thermoelectric performance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163457/2/adma202003730-sup-0001-SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163457/3/adma202003730_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163457/1/adma202003730.pd
Risk Prediction and Assessment: Duration, Infections, and Death Toll of the COVID-19 and Its Impact on China’s Economy
This study first analyzes the national and global infection status of the Coronavirus
Disease that emerged in 2019 (COVID-19). It then uses the trend comparison method to predict the inflection point and Key Point of the COVID-19 virus by comparison with the severe acute respiratory syndrome (SARS) graphs, followed by using the Autoregressive Integrated Moving Average model, Autoregressive Moving Average model, Seasonal Autoregressive Integrated Moving-Average with Exogenous Regressors, and Holt Winter’s Exponential Smoothing to predict infections, deaths, and GDP in China. Finally, it discusses and assesses the impact of these results.
This study argues that even if the risks and impacts of the epidemic are significant, China’s economy
will continue to maintain steady development
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
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