The vulnerability of deep neural networks to adversarial attacks has raised significant concerns about the security and reliability of artificial intelligence systems. Adversarial training is an effective approach to enhance adversarial robustness. To address the issue that existing methods adopt fixed adversarial sample generation strategies but neglect the importance of the adversarial sample generation phase for adversarial training, an adversarial training method was proposed based on adaptive attack strength. Firstly, the clean sample and the adversarial sample were input into the model to obtain the output. Then, the difference between the model outputs of the clean sample and the adversarial sample was calculated. Finally, the change of the difference compared with the previous moment was measured to automatically adjust the strength of the adversarial sample. Comprehensive experimental results on three benchmark datasets demonstrate that compared with the baseline method Adversarial Training with Projected Gradient Descent (PGD-AT), the proposed method improves the robust precision under AA (AutoAttack) attack by 1.92, 1.50 and 3.35 percentage points on three benchmark datasets, respectively, and the proposed method outperforms the state-of-the-art defense method Adversarial Training with Learnable Attack Strategy (LAS-AT) in terms of robustness and natural accuracy. Furthermore, from the perspective of data augmentation, the proposed method can effectively address the problem of diminishing augmentation effect during adversarial training.
Aiming at the problem of low multi-task offloading efficiency in the “cloud+edge” hybrid environment composed of “central cloud server and multiple edge servers”, a task offloading method based on probabilistic performance awareness and evolutionary game theory was proposed. Firstly, in a “cloud + edge” hybrid environment composed of “central cloud server and multiple edge servers”, assuming that all the edge servers distributed in it had time-varying volatility performance, the historical performance data of edge cloud servers was probabilistically analyzed by a task offloading method based on probabilistic performance awareness and evolutionary game theory for obtaining the evolutionary game model. Then, an Evolutionary Stability Strategy (ESS) of service offloading was generated to guarantee that each user could offload tasks on the premise of high satisfaction rate. Simulation experiments were carried out based on the cloud edge resource locations dataset and the cloud service performance test dataset, the test and comparison of different methods were carried out on 24 continuous time windows. Experimental results show that, the proposed method is better than traditional task offloading methods such as Greedy algorithm, Genetic Algorithm (GA), and Nash-based Game algorithm in many performance indexes. Compared with the three comparison methods, the proposed method has the average user satisfaction rate higher by 13.7%, 117.0%, 13.8% respectively, the average offloading time lower by 6.5%, 24.9%, 8.3% respectively, and the average monetary cost lower by 67.9%, 88.7%, 18.0% respectively.
This paper introduced the research works on all kinds of chain code used in image processing and pattern recognition and a new chain code named Improved Compressed Vertex Chain Code (ICVCC) was proposed based on Compressed Vertex Chain Code (CVCC). ICVCC added one code value compared with CVCC and adopted Huffman coding to encode each code value to achieve a set of chain code with unequal length. The expression ability per code, average length and efficiency as well as compression ratio with respect to 8-Directions Freeman Chain Code (8DFCC) were calculated respectively through the statistis a large number of images. The experimental results show that the efficiency of ICVCC proposed this paper is the highest and compression ratio is ideal.
The events correlation techniques in security integration management systems were introduced. A normal architecture of the correlation engine was introduced, and some discussions on the critical technologies and the main achievements in the field were put forward. The directions of the technology development were analyzed and evaluated, such as pattern obtainment, engine distribution and performance promotion. At last, a solution based on hierarchical rules to correlate events was presented.