5,029 research outputs found
PartCom: Part Composition Learning for 3D Open-Set Recognition
3D recognition is the foundation of 3D deep learning in many emerging fields,
such as autonomous driving and robotics.Existing 3D methods mainly focus on the
recognition of a fixed set of known classes and neglect possible unknown
classes during testing. These unknown classes may cause serious accidents in
safety-critical applications, i.e. autonomous driving. In this work, we make a
first attempt to address 3D open-set recognition (OSR) so that a classifier can
recognize known classes as well as be aware of unknown classes. We analyze
open-set risks in the 3D domain and point out the overconfidence and
under-representation problems that make existing methods perform poorly on the
3D OSR task. To resolve above problems, we propose a novel part prototype-based
OSR method named PartCom. We use part prototypes to represent a 3D shape as a
part composition, since a part composition can represent the overall structure
of a shape and can help distinguish different known classes and unknown ones.
Then we formulate two constraints on part prototypes to ensure their
effectiveness. To reduce open-set risks further, we devise a PUFS module to
synthesize unknown features as representatives of unknown samples by mixing up
part composite features of different classes. We conduct experiments on three
kinds of 3D OSR tasks based on both CAD shape dataset and scan shape dataset.
Extensive experiments show that our method is powerful in classifying known
classes and unknown ones and can attain much better results than SOTA baselines
on all 3D OSR tasks. The project will be released
Geometric effects of a quarter of corrugated torus
In the spirit of the thin-layer quantization scheme, we give the effective
Shr\"{o}dinger equation for a particle confined to a corrugated torus, in which
the geometric potential is substantially changed by corrugation. We find the
attractive wells reconstructed by the corrugation not being at identical
depths, which is strikingly different from that of a corrugated nanotube,
especially in the inner side of the torus. By numerically calculating the
transmission probability, we find that the resonant tunneling peaks and the
transmission gaps are merged and broadened by the corrugation of the inner side
of torus. These results show that the quarter corrugated torus can be used not
only to connect two tubes with different radiuses in different directions, but
also to filter the particles with particular incident~energies.Comment: 7 pages, 8 figure
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