Icing is an important factor threatening aircraft flight safety.According to the requirements of airworthiness regulations,aircraft icing safety assessment is needed to be carried out based on the ice shapes formed un...Icing is an important factor threatening aircraft flight safety.According to the requirements of airworthiness regulations,aircraft icing safety assessment is needed to be carried out based on the ice shapes formed under different icing conditions.Due to the complexity of the icing process,the rapid assessment of ice shape remains an important challenge.In this paper,an efficient prediction model of aircraft icing is established based on the deep belief network(DBN)and the stacked auto-encoder(SAE),which are all deep neural networks.The detailed network structures are designed and then the networks are trained according to the samples obtained by the icing numerical computation.After that the model is applied on the ice shape evaluation of NACA0012 airfoil.The results show that the model can accurately capture the nonlinear behavior of aircraft icing and thus make an excellent ice shape prediction.The model provides an important tool for aircraft icing analysis.展开更多
文摘针对现有恶意域名检测方法检测时间开销大、对新出现或新变种的恶意域名检测精度不高的问题,提出一种基于无监督自适应模糊聚类的多家族恶意域名细粒度检测方法。该方法首先利用词向量映射网络(Bidirectional Encoder Representation from Transformers,BERT)将域名字符串映射为词向量矩阵;然后,利用深度自编码网络的编解码模块实现域名字符串向量矩阵的特征提取;最后,引入一种自适应模糊聚类算法实现多家族恶意域名和合法域名在隐空间中的特征聚类。通过在多个家族恶意域名和常见域名数据集上进行测试,实验结果表明所提出算法可以在二分类任务中实现97.71%的准确率,在8个家族的细粒度多分类任务上可以实现96.25%的准确率。综合检测性能优于当前主流的恶意域名检测算法。同时,所提出域名具有较低的时间开销,这为实时过滤恶意域名、预防恶意域名的入侵攻击提供了一种新的手段。
基金supported in part by the National Natural Science Foundation of China(No.51606213)the National Major Science and Technology Projects(No.J2019-III-0010-0054)。
文摘Icing is an important factor threatening aircraft flight safety.According to the requirements of airworthiness regulations,aircraft icing safety assessment is needed to be carried out based on the ice shapes formed under different icing conditions.Due to the complexity of the icing process,the rapid assessment of ice shape remains an important challenge.In this paper,an efficient prediction model of aircraft icing is established based on the deep belief network(DBN)and the stacked auto-encoder(SAE),which are all deep neural networks.The detailed network structures are designed and then the networks are trained according to the samples obtained by the icing numerical computation.After that the model is applied on the ice shape evaluation of NACA0012 airfoil.The results show that the model can accurately capture the nonlinear behavior of aircraft icing and thus make an excellent ice shape prediction.The model provides an important tool for aircraft icing analysis.
