This study presents a framework for predicting geological characteristics based on integrating a stacking classification algorithm(SCA) with a grid search(GS) and K-fold cross validation(K-CV). The SCA includes two le...This study presents a framework for predicting geological characteristics based on integrating a stacking classification algorithm(SCA) with a grid search(GS) and K-fold cross validation(K-CV). The SCA includes two learner layers: a primary learner’s layer and meta-classifier layer. The accuracy of the SCA can be improved by using the GS and K-CV. The GS was developed to match the hyper-parameters and optimise complicated problems. The K-CV is commonly applied to changing the validation set in a training set. In general, a GS is usually combined with K-CV to produce a corresponding evaluation index and select the best hyper-parameters. The torque penetration index(TPI) and field penetration index(FPI) are proposed based on shield parameters to express the geological characteristics. The elbow method(EM) and silhouette coefficient(Si) are employed to determine the types of geological characteristics(K) in a Kmeans++ algorithm. A case study on mixed ground in Guangzhou is adopted to validate the applicability of the developed model. The results show that with the developed framework, the four selected parameters, i.e. thrust, advance rate, cutterhead rotation speed and cutterhead torque, can be used to effectively predict the corresponding geological characteristics.展开更多
在分布式物联网的大规模应用背景下,各实体设备中密码技术作为信息安全的底层支撑架构,正面临着侧信道攻击(SCA)这一物理层安全威胁的严峻挑战. SM4分组密码算法作为我国自主研制的商用密码算法标准,已深度集成于分布式物联网安全协议中...在分布式物联网的大规模应用背景下,各实体设备中密码技术作为信息安全的底层支撑架构,正面临着侧信道攻击(SCA)这一物理层安全威胁的严峻挑战. SM4分组密码算法作为我国自主研制的商用密码算法标准,已深度集成于分布式物联网安全协议中,但其实现层面的侧信道脆弱性问题亟待解决.针对SM4密钥扩展算法的侧信道攻击研究存在空白,现有攻击方法多依赖多能迹统计特性,而单能迹攻击研究匮乏.研究提出一种基于贝叶斯网络结合建模侧信道攻击的单能迹侧信道攻击方法,针对单条能量轨迹,通过构建概率图模型,结合置信传播算法,实现对轮子密钥的高效推测,进而恢复主密钥.仿真实验与实测实验表明该攻击方法有效,在理想实测环境下主密钥恢复成功率达85.74%,即使在实测能迹中添加大量高斯白噪声,使得信噪比仅为10 d B的条件下,成功率仍可达70%.与传统方法相比,所提方法在成功率、所需能量轨迹数量和攻击时间等方面优势显著,为分布式物联网系统含密设备的侧信道攻击研究提供了新的思路与技术手段,也为相关防护设计提供了理论依据和参考.展开更多
基金funded by“The Pearl River Talent Recruitment Program”of Guangdong Province in 2019(Grant No.2019CX01G338)the Research Funding of Shantou University for New Faculty Member(Grant No.NTF19024-2019).
文摘This study presents a framework for predicting geological characteristics based on integrating a stacking classification algorithm(SCA) with a grid search(GS) and K-fold cross validation(K-CV). The SCA includes two learner layers: a primary learner’s layer and meta-classifier layer. The accuracy of the SCA can be improved by using the GS and K-CV. The GS was developed to match the hyper-parameters and optimise complicated problems. The K-CV is commonly applied to changing the validation set in a training set. In general, a GS is usually combined with K-CV to produce a corresponding evaluation index and select the best hyper-parameters. The torque penetration index(TPI) and field penetration index(FPI) are proposed based on shield parameters to express the geological characteristics. The elbow method(EM) and silhouette coefficient(Si) are employed to determine the types of geological characteristics(K) in a Kmeans++ algorithm. A case study on mixed ground in Guangzhou is adopted to validate the applicability of the developed model. The results show that with the developed framework, the four selected parameters, i.e. thrust, advance rate, cutterhead rotation speed and cutterhead torque, can be used to effectively predict the corresponding geological characteristics.
文摘在分布式物联网的大规模应用背景下,各实体设备中密码技术作为信息安全的底层支撑架构,正面临着侧信道攻击(SCA)这一物理层安全威胁的严峻挑战. SM4分组密码算法作为我国自主研制的商用密码算法标准,已深度集成于分布式物联网安全协议中,但其实现层面的侧信道脆弱性问题亟待解决.针对SM4密钥扩展算法的侧信道攻击研究存在空白,现有攻击方法多依赖多能迹统计特性,而单能迹攻击研究匮乏.研究提出一种基于贝叶斯网络结合建模侧信道攻击的单能迹侧信道攻击方法,针对单条能量轨迹,通过构建概率图模型,结合置信传播算法,实现对轮子密钥的高效推测,进而恢复主密钥.仿真实验与实测实验表明该攻击方法有效,在理想实测环境下主密钥恢复成功率达85.74%,即使在实测能迹中添加大量高斯白噪声,使得信噪比仅为10 d B的条件下,成功率仍可达70%.与传统方法相比,所提方法在成功率、所需能量轨迹数量和攻击时间等方面优势显著,为分布式物联网系统含密设备的侧信道攻击研究提供了新的思路与技术手段,也为相关防护设计提供了理论依据和参考.
