Network security problems bring many imperceptible threats to the integrity of data and the reliability of device services,so proposing a network intrusion detection model with high reliability is of great research si...Network security problems bring many imperceptible threats to the integrity of data and the reliability of device services,so proposing a network intrusion detection model with high reliability is of great research significance for network security.Due to the strong generalization of invalid features during training process,it is more difficult for single autoencoder intrusion detection model to obtain effective results.A network intrusion detection model based on the Ensemble of Denoising Adversarial Autoencoder(EDAAE)was proposed,which had higher accuracy and reliability compared to the traditional anomaly detection model.Using the adversarial learning idea of Adversarial Autoencoder(AAE),the discriminator module was added to the original model,and the encoder part was used as the generator.The distribution of the hidden space of the data generated by the encoder matched with the distribution of the original data.The generalization of the model to the invalid features was also reduced to improve the detection accuracy.At the same time,the denoising autoencoder and integrated operation was introduced to prevent overfitting in the adversarial learning process.Experiments on the CICIDS2018 traffic dataset showed that the proposed intrusion detection model achieves an Accuracy of 95.23%,which out performs traditional self-encoders and other existing intrusion detection models methods in terms of overall performance.展开更多
Time series analysis is a key technology for medical diagnosis,weather forecasting and financial prediction systems.However,missing data frequently occur during data recording,posing a great challenge to data mining t...Time series analysis is a key technology for medical diagnosis,weather forecasting and financial prediction systems.However,missing data frequently occur during data recording,posing a great challenge to data mining tasks.In this study,we propose a novel time series data representation-based denoising autoencoder(DAE)for the reconstruction of missing values.Two data representation methods,namely,recurrence plot(RP)and Gramian angular field(GAF),are used to transform the raw time series to a 2D matrix for establishing the temporal correlations between different time intervals and extracting the structural patterns from the time series.Then an improved DAE is proposed to reconstruct the missing values from the 2D representation of time series.A comprehensive comparison is conducted amongst the different representations on standard datasets.Results show that the 2D representations have a lower reconstruction error than the raw time series,and the RP representation provides the best outcome.This work provides useful insights into the better reconstruction of missing values in time series analysis to considerably improve the reliability of timevarying system.展开更多
在实际监测任务中,及时有效地识别飞行模式至关重要。然而,现有的飞行模式识别方法主观性强、模式单一,限制了在复杂情况下的飞行监控能力,在实际应用中有局限性,进而导致模式边界定位不精确、识别精度低。为此提出一种基于敏感边界和...在实际监测任务中,及时有效地识别飞行模式至关重要。然而,现有的飞行模式识别方法主观性强、模式单一,限制了在复杂情况下的飞行监控能力,在实际应用中有局限性,进而导致模式边界定位不精确、识别精度低。为此提出一种基于敏感边界和长飞行序列的飞行模式智能识别方法(Intelligent Flight Pattern Recognition Method for Sensitive Boundaries and Long Flight Sequences, IFPRM-SBLFS),以对飞行模式进行智能识别。为了更好地探索多模式飞行参数的空间关系,设计自适应图嵌入,针对不同持续时间的飞行模式提出去噪深度多尺度自动编码器,以及用于减轻模型损失的分类加权焦点损失和回归联合时空交集损失。为验证所提方法的优越性,采集多架民用航班的真实参数,涵盖11种飞行模式,通过人工标注构建飞行模式数据集。仿真计算结果表明:新模型能够在连续飞行架次中自动区分不同的飞行模式,并准确提取模式边界,识别准确率达到了99.07%,且无需任何预处理或后处理;新的智能识别方法可以有效提高精确度和敏感边界的飞行模式识别效果。展开更多
为有效解决多维时间序列(multivariate time series, MTS)无监督异常检测模型中自编码器模块容易拟合异常样本、正常MTS样本对应的隐空间特征可能被重构为异常MTS的问题,设计一种具有三重生成对抗的MTS异常检测模型。以LSTM自编码器为...为有效解决多维时间序列(multivariate time series, MTS)无监督异常检测模型中自编码器模块容易拟合异常样本、正常MTS样本对应的隐空间特征可能被重构为异常MTS的问题,设计一种具有三重生成对抗的MTS异常检测模型。以LSTM自编码器为生成器,基于重构误差生成伪标签,由判别器区分经伪标签过滤后的重构MTS和原始MTS;采用两次对抗训练将LSTM自编码器的隐空间约束为均匀分布,减少LSTM自编码器隐空间特征重构出异常MTS的可能性。多个公开MTS数据集上的实验结果表明,T-GAN能在带有污染数据的训练集上更好学习正常MTS分布,取得较高的异常检测效果。展开更多
文摘Network security problems bring many imperceptible threats to the integrity of data and the reliability of device services,so proposing a network intrusion detection model with high reliability is of great research significance for network security.Due to the strong generalization of invalid features during training process,it is more difficult for single autoencoder intrusion detection model to obtain effective results.A network intrusion detection model based on the Ensemble of Denoising Adversarial Autoencoder(EDAAE)was proposed,which had higher accuracy and reliability compared to the traditional anomaly detection model.Using the adversarial learning idea of Adversarial Autoencoder(AAE),the discriminator module was added to the original model,and the encoder part was used as the generator.The distribution of the hidden space of the data generated by the encoder matched with the distribution of the original data.The generalization of the model to the invalid features was also reduced to improve the detection accuracy.At the same time,the denoising autoencoder and integrated operation was introduced to prevent overfitting in the adversarial learning process.Experiments on the CICIDS2018 traffic dataset showed that the proposed intrusion detection model achieves an Accuracy of 95.23%,which out performs traditional self-encoders and other existing intrusion detection models methods in terms of overall performance.
文摘Time series analysis is a key technology for medical diagnosis,weather forecasting and financial prediction systems.However,missing data frequently occur during data recording,posing a great challenge to data mining tasks.In this study,we propose a novel time series data representation-based denoising autoencoder(DAE)for the reconstruction of missing values.Two data representation methods,namely,recurrence plot(RP)and Gramian angular field(GAF),are used to transform the raw time series to a 2D matrix for establishing the temporal correlations between different time intervals and extracting the structural patterns from the time series.Then an improved DAE is proposed to reconstruct the missing values from the 2D representation of time series.A comprehensive comparison is conducted amongst the different representations on standard datasets.Results show that the 2D representations have a lower reconstruction error than the raw time series,and the RP representation provides the best outcome.This work provides useful insights into the better reconstruction of missing values in time series analysis to considerably improve the reliability of timevarying system.
文摘在实际监测任务中,及时有效地识别飞行模式至关重要。然而,现有的飞行模式识别方法主观性强、模式单一,限制了在复杂情况下的飞行监控能力,在实际应用中有局限性,进而导致模式边界定位不精确、识别精度低。为此提出一种基于敏感边界和长飞行序列的飞行模式智能识别方法(Intelligent Flight Pattern Recognition Method for Sensitive Boundaries and Long Flight Sequences, IFPRM-SBLFS),以对飞行模式进行智能识别。为了更好地探索多模式飞行参数的空间关系,设计自适应图嵌入,针对不同持续时间的飞行模式提出去噪深度多尺度自动编码器,以及用于减轻模型损失的分类加权焦点损失和回归联合时空交集损失。为验证所提方法的优越性,采集多架民用航班的真实参数,涵盖11种飞行模式,通过人工标注构建飞行模式数据集。仿真计算结果表明:新模型能够在连续飞行架次中自动区分不同的飞行模式,并准确提取模式边界,识别准确率达到了99.07%,且无需任何预处理或后处理;新的智能识别方法可以有效提高精确度和敏感边界的飞行模式识别效果。
文摘为有效解决多维时间序列(multivariate time series, MTS)无监督异常检测模型中自编码器模块容易拟合异常样本、正常MTS样本对应的隐空间特征可能被重构为异常MTS的问题,设计一种具有三重生成对抗的MTS异常检测模型。以LSTM自编码器为生成器,基于重构误差生成伪标签,由判别器区分经伪标签过滤后的重构MTS和原始MTS;采用两次对抗训练将LSTM自编码器的隐空间约束为均匀分布,减少LSTM自编码器隐空间特征重构出异常MTS的可能性。多个公开MTS数据集上的实验结果表明,T-GAN能在带有污染数据的训练集上更好学习正常MTS分布,取得较高的异常检测效果。
文摘在高压并联电抗器声纹信号监测系统中,长时海量无标签声纹的高维非平稳性导致特征提取困难、无监督聚类适应性差。由此提出了一种基于深度自适应K-means++算法(deep adaptive K-means++clustering algorithm,DAKCA)的750 kV电抗器声纹聚类方法。首先通过采用两阶段无监督策略微调的改进堆叠稀疏自编码器(stacked sparse autoencoder,SSAE),对快速傅里叶变换后的归一化频域数据提取电抗器原始声纹32维深度特征。进一步提出了依据最近邻聚类有效性指标(clustering validation index based on nearest neighbors,CVNN)的自适应K-means++聚类算法,构建了能自适应确定最优聚类个数的电抗器声纹聚类模型。最后通过西北地区某750 kV电抗器实测声纹数据集进行了验证。结果表明,DAKCA算法对无标签声纹数据在不同样本均衡程度下能够稳定提取32维深度特征,并实现最优聚类,为直接高效利用电抗器无标签声纹数据提供了参考。
