11,518 research outputs found
Tracking by Animation: Unsupervised Learning of Multi-Object Attentive Trackers
Online Multi-Object Tracking (MOT) from videos is a challenging computer
vision task which has been extensively studied for decades. Most of the
existing MOT algorithms are based on the Tracking-by-Detection (TBD) paradigm
combined with popular machine learning approaches which largely reduce the
human effort to tune algorithm parameters. However, the commonly used
supervised learning approaches require the labeled data (e.g., bounding boxes),
which is expensive for videos. Also, the TBD framework is usually suboptimal
since it is not end-to-end, i.e., it considers the task as detection and
tracking, but not jointly. To achieve both label-free and end-to-end learning
of MOT, we propose a Tracking-by-Animation framework, where a differentiable
neural model first tracks objects from input frames and then animates these
objects into reconstructed frames. Learning is then driven by the
reconstruction error through backpropagation. We further propose a
Reprioritized Attentive Tracking to improve the robustness of data association.
Experiments conducted on both synthetic and real video datasets show the
potential of the proposed model. Our project page is publicly available at:
https://github.com/zhen-he/tracking-by-animationComment: CVPR 201
Interplay between multi-spin and chiral spin interactions on triangular lattice
We investigate the spin- nearest-neighber Heisenberg model with
the four-site ring-exchange and chiral interaction on the
triangular lattice by using the variational Monte Carlo method. The term
induces the quadratic band touching (QBT) quantum spin liquid (QSL) with only a
spinon pairing (without hopping term), the nodal -wave QSL and U(1)
QSL with a finite spinon Fermi surface progressively. The effect of the chiral
interaction can enrich the phase diagram with two interesting chiral
QSLs (topological orders) with the same quantized Chern number and ground-state degeneracy GSD = 2, namely the U(1) chiral spin
liquid (CSL) and Z -wave QSL. The nodal -wave QSL is fragile and
will turn to the Z QSL with any finite within our numerical
calculation. However, in the process from QBT to the Z QSL with the
increase of , an exotic crossover region is found. In this region, the
previous QBT state acquires a small hopping term so that it opens a small gap
at the otherwise band touching points, and leads to an energy minimum which is
energetically more favorable compared to another competitive local minimum from
the Z QSL. We dub this state as the proximate QBT QSL and it gives
way to the Z QSL eventually. Therefore, the cooperation of the
and terms favors mostly the Z -wave QSL, so that this phase
occupies the largest region in the phase diagram
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