During bipedal walking,it is critical to detect and adjust the robot postures by feedback control to maintain its normal state amidst multi-source random disturbances arising from some unavoidable uncertain factors.Th...During bipedal walking,it is critical to detect and adjust the robot postures by feedback control to maintain its normal state amidst multi-source random disturbances arising from some unavoidable uncertain factors.The radical basis function（RBF）neural network model of a five-link biped robot is established,and two certain disturbances and a randomly uncertain disturbance are then mixed with the optimal torques in the network model to study the performance of the biped robot by several evaluation indices and a specific Poincar′e map.In contrast with the simulations,the response varies as desired under optimal inputting while the output is fluctuating in the situation of disturbance driving.Simulation results from noise inputting also show that the dynamics of the robot is less sensitive to the disturbance of knee joint input of the swing leg than those of the other three joints,the response errors of the biped will be increasing with higher disturbance levels,and especially there are larger output fluctuations in the knee and hip joints of the swing leg.展开更多
Although function projective synchronization in complex dynamical networks has been extensively studied in the literature, few papers deal with the problem between two different complex networks with correlated random...Although function projective synchronization in complex dynamical networks has been extensively studied in the literature, few papers deal with the problem between two different complex networks with correlated random disturbances. In this paper, we present some novel techniques to analyze the problem of synchronization. A probability approach is introduced to obtain an almost sure synchronization criterion. We also present some efficient approaches to analyze the problem of exponential synchronization. For the problem of synchronization in some complex networks, our approaches not only can replace the LaSalle-type theorem but also allow improvements of existing results in the literature. Finally, some numerical examples are provided to demonstrate the effectiveness of the proposed approaches.展开更多
The guaranty of power system stability during a random disturbances, requires systematically a wide knowledge of the disturbance components in one hand and their range of variation in the other hand. The major problem...The guaranty of power system stability during a random disturbances, requires systematically a wide knowledge of the disturbance components in one hand and their range of variation in the other hand. The major problem lies in the approach taken to the identification of the main components of this type of disturbances, Control strategy will only be effective if these disturbances are acceptably modeled. A better approximation of the dynamic components of these disturbances likely to affect power systems, leading to the implementation of a highly reliable control strategy. The identification and evaluation of dynamic components of these disturbances will be the major objective of this study. The control strategy of such disturbances, random, will be develooed to adant itto a wind farm connected to an electrical network.展开更多
In this paper, a method of power quality disturbance classification based on random matrix theory (RMT) is proposed. The method utilizes the power quality disturbance signal to construct a random matrix. By analyzing ...In this paper, a method of power quality disturbance classification based on random matrix theory (RMT) is proposed. The method utilizes the power quality disturbance signal to construct a random matrix. By analyzing the mean spectral radius (MSR) variation of the random matrix, the type and time of occurrence of power quality disturbance are classified. In this paper, the random matrix theory is used to analyze the voltage sag, swell and interrupt perturbation signals to classify the occurrence time, duration of the disturbance signal and thedepth of voltage sag or swell. Examples show that the method has strong anti-noise ability.展开更多
作为密码应用核心要素,真随机数发挥着不可替代的作用.为保证其质量,真随机数大多基于随机物理现象构造的熵源产生,这也使得其易遭受由环境引入或攻击者恶意施加的扰动影响,进而对密码应用安全产生威胁.为确保真随机数的质量,当前各主...作为密码应用核心要素,真随机数发挥着不可替代的作用.为保证其质量,真随机数大多基于随机物理现象构造的熵源产生,这也使得其易遭受由环境引入或攻击者恶意施加的扰动影响,进而对密码应用安全产生威胁.为确保真随机数的质量,当前各主要国际标准均明确要求真随机数发生器(True Random Number Generator,TRNG)应针对熵源生成的原始随机数(raw random numbers)提供在线监测功能.然而,由于现有在线监测大多基于抽样统计方法构建,导致其在实际应用中存在实现复杂、耗费资源大等问题;另一方面,由于统计模型偏差及熵源输出分布受扰动因素影响等原因,使得现有在线监测方法普遍存在过估计问题.本文以当前广泛采用的振荡环熵源为对象,对扰动场景下熵源特性变异成因及影响进行了深入分析,提出了用于刻画熵源特性的异源同构周期计数差表征方法,并结合变异阈值的标定,构建了具备高准确度、强实时性的熵源在线监测方法.与当前各主要在线监测方法相比,该方法在资源耗费方面具有明显优势,能够实时反映扰动场景下熵源在噪声分量、扰动感应耦合等方面的变异情况,实现对TRNG健康特性的有效监测.展开更多
为解决电能质量扰动的分类问题,利用多分辨奇异值分解(Singular Value Decomposition, SVD)的信号逐层分解方式,提出基于多分辨SVD包与随机森林(Multi-Resolution SVD and Random Forest, MRSVD-RF)的电能质量扰动分类方法。通过实验证...为解决电能质量扰动的分类问题,利用多分辨奇异值分解(Singular Value Decomposition, SVD)的信号逐层分解方式,提出基于多分辨SVD包与随机森林(Multi-Resolution SVD and Random Forest, MRSVD-RF)的电能质量扰动分类方法。通过实验证明了该算法对单一和复合电能质量信号的分类效果明显优于分解结构相似的基于的小波包的信号分解方式,比较了分类器模型的选择和特征提取数量对算法性能的影响。展开更多
基金supported by the Science Fund for Creative Research Groups of National Natural Science Foundation of China(51221004)the National Natural Science Foundation of China(11172260,11372270,and 51375434)+2 种基金the Higher School Specialized Research Fund for the Doctoral Program(20110101110016)the Science and technology project of Zhejiang Province(2013C31086)the Fundamental Research Funds forthe Central Universities of China(2013XZZX005)
文摘During bipedal walking,it is critical to detect and adjust the robot postures by feedback control to maintain its normal state amidst multi-source random disturbances arising from some unavoidable uncertain factors.The radical basis function（RBF）neural network model of a five-link biped robot is established,and two certain disturbances and a randomly uncertain disturbance are then mixed with the optimal torques in the network model to study the performance of the biped robot by several evaluation indices and a specific Poincar′e map.In contrast with the simulations,the response varies as desired under optimal inputting while the output is fluctuating in the situation of disturbance driving.Simulation results from noise inputting also show that the dynamics of the robot is less sensitive to the disturbance of knee joint input of the swing leg than those of the other three joints,the response errors of the biped will be increasing with higher disturbance levels,and especially there are larger output fluctuations in the knee and hip joints of the swing leg.
基金Project supported by the National Natural Science Foundation of China(Grant No.61273015)
文摘Although function projective synchronization in complex dynamical networks has been extensively studied in the literature, few papers deal with the problem between two different complex networks with correlated random disturbances. In this paper, we present some novel techniques to analyze the problem of synchronization. A probability approach is introduced to obtain an almost sure synchronization criterion. We also present some efficient approaches to analyze the problem of exponential synchronization. For the problem of synchronization in some complex networks, our approaches not only can replace the LaSalle-type theorem but also allow improvements of existing results in the literature. Finally, some numerical examples are provided to demonstrate the effectiveness of the proposed approaches.
文摘The guaranty of power system stability during a random disturbances, requires systematically a wide knowledge of the disturbance components in one hand and their range of variation in the other hand. The major problem lies in the approach taken to the identification of the main components of this type of disturbances, Control strategy will only be effective if these disturbances are acceptably modeled. A better approximation of the dynamic components of these disturbances likely to affect power systems, leading to the implementation of a highly reliable control strategy. The identification and evaluation of dynamic components of these disturbances will be the major objective of this study. The control strategy of such disturbances, random, will be develooed to adant itto a wind farm connected to an electrical network.
文摘In this paper, a method of power quality disturbance classification based on random matrix theory (RMT) is proposed. The method utilizes the power quality disturbance signal to construct a random matrix. By analyzing the mean spectral radius (MSR) variation of the random matrix, the type and time of occurrence of power quality disturbance are classified. In this paper, the random matrix theory is used to analyze the voltage sag, swell and interrupt perturbation signals to classify the occurrence time, duration of the disturbance signal and thedepth of voltage sag or swell. Examples show that the method has strong anti-noise ability.
基金supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(416811,416812)National Natural Science Foundation of China(61573003)part by the Scientific Research Fund of Hunan Provincial Education Department of China(15k026)
文摘作为密码应用核心要素,真随机数发挥着不可替代的作用.为保证其质量,真随机数大多基于随机物理现象构造的熵源产生,这也使得其易遭受由环境引入或攻击者恶意施加的扰动影响,进而对密码应用安全产生威胁.为确保真随机数的质量,当前各主要国际标准均明确要求真随机数发生器(True Random Number Generator,TRNG)应针对熵源生成的原始随机数(raw random numbers)提供在线监测功能.然而,由于现有在线监测大多基于抽样统计方法构建,导致其在实际应用中存在实现复杂、耗费资源大等问题;另一方面,由于统计模型偏差及熵源输出分布受扰动因素影响等原因,使得现有在线监测方法普遍存在过估计问题.本文以当前广泛采用的振荡环熵源为对象,对扰动场景下熵源特性变异成因及影响进行了深入分析,提出了用于刻画熵源特性的异源同构周期计数差表征方法,并结合变异阈值的标定,构建了具备高准确度、强实时性的熵源在线监测方法.与当前各主要在线监测方法相比,该方法在资源耗费方面具有明显优势,能够实时反映扰动场景下熵源在噪声分量、扰动感应耦合等方面的变异情况,实现对TRNG健康特性的有效监测.
文摘为解决电能质量扰动的分类问题,利用多分辨奇异值分解(Singular Value Decomposition, SVD)的信号逐层分解方式,提出基于多分辨SVD包与随机森林(Multi-Resolution SVD and Random Forest, MRSVD-RF)的电能质量扰动分类方法。通过实验证明了该算法对单一和复合电能质量信号的分类效果明显优于分解结构相似的基于的小波包的信号分解方式,比较了分类器模型的选择和特征提取数量对算法性能的影响。
