625 research outputs found
Multi-scale 3D Convolution Network for Video Based Person Re-Identification
This paper proposes a two-stream convolution network to extract spatial and
temporal cues for video based person Re-Identification (ReID). A temporal
stream in this network is constructed by inserting several Multi-scale 3D (M3D)
convolution layers into a 2D CNN network. The resulting M3D convolution network
introduces a fraction of parameters into the 2D CNN, but gains the ability of
multi-scale temporal feature learning. With this compact architecture, M3D
convolution network is also more efficient and easier to optimize than existing
3D convolution networks. The temporal stream further involves Residual
Attention Layers (RAL) to refine the temporal features. By jointly learning
spatial-temporal attention masks in a residual manner, RAL identifies the
discriminative spatial regions and temporal cues. The other stream in our
network is implemented with a 2D CNN for spatial feature extraction. The
spatial and temporal features from two streams are finally fused for the video
based person ReID. Evaluations on three widely used benchmarks datasets, i.e.,
MARS, PRID2011, and iLIDS-VID demonstrate the substantial advantages of our
method over existing 3D convolution networks and state-of-art methods.Comment: AAAI, 201
Collaborative Spatio-temporal Feature Learning for Video Action Recognition
Spatio-temporal feature learning is of central importance for action
recognition in videos. Existing deep neural network models either learn spatial
and temporal features independently (C2D) or jointly with unconstrained
parameters (C3D). In this paper, we propose a novel neural operation which
encodes spatio-temporal features collaboratively by imposing a weight-sharing
constraint on the learnable parameters. In particular, we perform 2D
convolution along three orthogonal views of volumetric video data,which learns
spatial appearance and temporal motion cues respectively. By sharing the
convolution kernels of different views, spatial and temporal features are
collaboratively learned and thus benefit from each other. The complementary
features are subsequently fused by a weighted summation whose coefficients are
learned end-to-end. Our approach achieves state-of-the-art performance on
large-scale benchmarks and won the 1st place in the Moments in Time Challenge
2018. Moreover, based on the learned coefficients of different views, we are
able to quantify the contributions of spatial and temporal features. This
analysis sheds light on interpretability of the model and may also guide the
future design of algorithm for video recognition.Comment: CVPR 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
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