Strength-Adaptive Adversarial Training

Adversarial training (AT) is proved to reliably improve network's robustness against adversarial data. However, current AT with a pre-specified perturbation budget has limitations in learning a robust network. Firstly, applying a pre-specified perturbation budget on networks of various model capacities will yield divergent degree of robustness disparity between natural and robust accuracies, which deviates from robust network's desideratum. Secondly, the attack strength of adversarial training data constrained by the pre-specified perturbation budget fails to upgrade as the growth of network robustness, which leads to robust overfitting and further degrades the adversarial robustness. To overcome these limitations, we propose \emph{Strength-Adaptive Adversarial Training} (SAAT). Specifically, the adversary employs an adversarial loss constraint to generate adversarial training data. Under this constraint, the perturbation budget will be adaptively adjusted according to the training state of adversarial data, which can effectively avoid robust overfitting. Besides, SAAT explicitly constrains the attack strength of training data through the adversarial loss, which manipulates model capacity scheduling during training, and thereby can flexibly control the degree of robustness disparity and adjust the tradeoff between natural accuracy and robustness. Extensive experiments show that our proposal boosts the robustness of adversarial training

J. Nanosci. Nanotechnol.

alpha-Fe(2)O(3) hollow micospheres have been successfully synthesized by solvothermal method at 200 degrees C. The synthesized products are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and the nitrogen adsorption-desorption isotherm technique. The alpha-Fe(2)O(3) hollow microspheres have an average diameter of 2-3 mu m, the shell consists of numerous aligned nanorods with length of about 200-400 nm. The effects of solvent and reaction time have been studied. The Ostwald ripening mechanism is proposed to account for the formation of alpha-Fe(2)O(3) hollow microspheres. Because of the porous hollow microstructure and large specific surface area, the microspheres were found to be effective sorbents for the removal of Cr(VI) ions from wastewater.alpha-Fe(2)O(3) hollow micospheres have been successfully synthesized by solvothermal method at 200 degrees C. The synthesized products are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and the nitrogen adsorption-desorption isotherm technique. The alpha-Fe(2)O(3) hollow microspheres have an average diameter of 2-3 mu m, the shell consists of numerous aligned nanorods with length of about 200-400 nm. The effects of solvent and reaction time have been studied. The Ostwald ripening mechanism is proposed to account for the formation of alpha-Fe(2)O(3) hollow microspheres. Because of the porous hollow microstructure and large specific surface area, the microspheres were found to be effective sorbents for the removal of Cr(VI) ions from wastewater