1,626 research outputs found
Read, Watch, and Move: Reinforcement Learning for Temporally Grounding Natural Language Descriptions in Videos
The task of video grounding, which temporally localizes a natural language
description in a video, plays an important role in understanding videos.
Existing studies have adopted strategies of sliding window over the entire
video or exhaustively ranking all possible clip-sentence pairs in a
pre-segmented video, which inevitably suffer from exhaustively enumerated
candidates. To alleviate this problem, we formulate this task as a problem of
sequential decision making by learning an agent which regulates the temporal
grounding boundaries progressively based on its policy. Specifically, we
propose a reinforcement learning based framework improved by multi-task
learning and it shows steady performance gains by considering additional
supervised boundary information during training. Our proposed framework
achieves state-of-the-art performance on ActivityNet'18 DenseCaption dataset
and Charades-STA dataset while observing only 10 or less clips per video.Comment: AAAI 201
The effect of Cr impurity to superconductivity in electron-doped BaFe2-xNixAs2
We use transport and magnetization measurements to study the effect of
Cr-doping to the phase diagram of the electron-doped superconducting
BaFe2-xNixAs2 iron pnictides. In principle, adding Cr to electron-doped
BaFe2-xNixAs2 should be equivalent to the effect of hole-doping. However, we
find that Cr doping suppresses superconductivity via impurity effect, while not
affecting the normal state resistivity above 100 K. We establish the phase
diagram of Cr-doped BaFe2-x-yNixCryAs2 iron pnictides, and demonstrate that
Cr-doping near optimal superconductivity restore the long-range
antiferromagnetic order suppressed by superconductivity.Comment: 10 pages, 5 figure
Fair Attribute Completion on Graph with Missing Attributes
Tackling unfairness in graph learning models is a challenging task, as the
unfairness issues on graphs involve both attributes and topological structures.
Existing work on fair graph learning simply assumes that attributes of all
nodes are available for model training and then makes fair predictions. In
practice, however, the attributes of some nodes might not be accessible due to
missing data or privacy concerns, which makes fair graph learning even more
challenging. In this paper, we propose FairAC, a fair attribute completion
method, to complement missing information and learn fair node embeddings for
graphs with missing attributes. FairAC adopts an attention mechanism to deal
with the attribute missing problem and meanwhile, it mitigates two types of
unfairness, i.e., feature unfairness from attributes and topological unfairness
due to attribute completion. FairAC can work on various types of homogeneous
graphs and generate fair embeddings for them and thus can be applied to most
downstream tasks to improve their fairness performance. To our best knowledge,
FairAC is the first method that jointly addresses the graph attribution
completion and graph unfairness problems. Experimental results on benchmark
datasets show that our method achieves better fairness performance with less
sacrifice in accuracy, compared with the state-of-the-art methods of fair graph
learning. Code is available at: https://github.com/donglgcn/FairAC
The effect of geographic distance on independent directors’ performance from the perspective of inefficient investment
Geoeconomics has attracted sustained attention in recent years,
but the role of independent directors’ geographic distance in
investment efficiency remains unexplored. We explore the governance
effects of independent directors from a geographic location
perspective. Specifically, the Great Circle Distance Formula is
employed to calculate the geographic distance between the independent
directors and the enterprise. Then, we measure the inefficient
investment. Using a detailed sample in the Chinese market
from 2009 to 2018, we find that geographic distance is not conducive
to the functioning of independent directors and that there is a
positive relationship between independent directors’ geographic
distance and inefficient investment. The coefficients are robust to
multiple robustness checks. In addition, the positive effect of independent
directors’ geographic distance on inefficient investment
will increase (become more positive) when there is no high-speed
rail and the marketisation process is low in the enterprise’s location.
Mechanism tests show that geographic distance does affect inefficient
investment by inhibiting independent directors’ access to
information as well as their reputation. Our results have important
implications for investment policy and corporate governance
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