2,202 research outputs found
On the Importance of Backbone to the Adversarial Robustness of Object Detectors
Object detection is a critical component of various security-sensitive
applications, such as autonomous driving and video surveillance. However,
existing deep learning-based object detectors are vulnerable to adversarial
attacks, which poses a significant challenge to their reliability and safety.
Through experiments, we found that existing works on improving the adversarial
robustness of object detectors have given a false sense of security. We argue
that using adversarially pre-trained backbone networks is essential for
enhancing the adversarial robustness of object detectors. We propose a simple
yet effective recipe for fast adversarial fine-tuning on object detectors with
adversarially pre-trained backbones. Without any modifications to the structure
of object detectors, our recipe achieved significantly better adversarial
robustness than previous works. Moreover, we explore the potential of different
modern object detectors to improve adversarial robustness using our recipe and
demonstrate several interesting findings. Our empirical results set a new
milestone and deepen the understanding of adversarially robust object
detection. Code and trained checkpoints will be publicly available.Comment: 12 page
Development of a Transferable Reactive Force Field of P/H Systems: Application to the Chemical and Mechanical Properties of Phosphorene
ReaxFF provides a method to model reactive chemical systems in large-scale
molecular dynamics simulations. Here, we developed ReaxFF parameters for
phosphorus and hydrogen to give a good description of the chemical and
mechanical properties of pristine and defected black phosphorene. ReaxFF for
P/H is transferable to a wide range of phosphorus and hydrogen containing
systems including bulk black phosphorus, blue phosphorene, edge-hydrogenated
phosphorene, phosphorus clusters and phosphorus hydride molecules. The
potential parameters were obtained by conducting unbiased global optimization
with respect to a set of reference data generated by extensive ab initio
calculations. We extend ReaxFF by adding a 60{\deg} correction term which
significantly improves the description of phosphorus clusters. Emphasis has
been put on obtaining a good description of mechanical response of black
phosphorene with different types of defects. Compared to nonreactive SW
potential [1], ReaxFF for P/H systems provides a huge improvement in describing
the mechanical properties the pristine and defected black phosphorene and the
thermal stability of phosphorene nanotubes. A counterintuitive phenomenon is
observed that single vacancies weaken the black phosphorene more than double
vacancies with higher formation energy. Our results also show that mechanical
response of black phosphorene is more sensitive to defects for the zigzag
direction than for the armchair direction. Since ReaxFF allows straightforward
extensions to the heterogeneous systems, such as oxides, nitrides, ReaxFF
parameters for P/H systems build a solid foundation for the reactive force
field description of heterogeneous P systems, including P-containing 2D van der
Waals heterostructures, oxides, etc
- …