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时域随机驱动信号生成试验研究 被引量:2
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作者 陆勇星 郭家骅 《机械强度》 CAS CSCD 北大核心 2013年第6期749-754,共6页
将高阶累积量谱应用于多点随机振动控制环境试验中,生成时域随机驱动信号。通过建立三阶累积量谱(双谱)与自谱间的幅频与相位转换关系,经时域随机驱动信号验证性生成实验,揭示这层关系的存在。其次在多输入多输出线性系统理论假设前提下... 将高阶累积量谱应用于多点随机振动控制环境试验中,生成时域随机驱动信号。通过建立三阶累积量谱(双谱)与自谱间的幅频与相位转换关系,经时域随机驱动信号验证性生成实验,揭示这层关系的存在。其次在多输入多输出线性系统理论假设前提下,根据系统驱动、系统频响、系统响应间线性映射关系,通过双谱与自谱间的幅频与相位转换,经IFFT(iverse fast Fourier transform)变换生成满足试验控制要求的时域随机驱动信号。最后以一悬臂梁为试件,对其进行双输入、双输出随机振动控制环境模拟试验。试验结果表明:将双谱应用于多点随机振动控制试验中生成时域随机驱动信号的方法是可行有效的,同时也验证了双谱能抑制高斯白噪声的特性,这一点可通过所生成驱动信号的概率密度分布特征曲线(部分满足均匀分布)进行体现。 展开更多
关键词 高阶累积量谱 随机振动控制 双谱 自谱 随机驱动信号
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随机存取驱动器规格风云变幻DVD—RAM崭露头角
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作者 Rookie 《现代计算机(中旬刊)》 2000年第104期28-31,共4页
关键词 DVD-RAM 随机存取驱动 光碟存储系统
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连续振动载荷在线复现控制技术研究
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作者 严侠 王军评 +1 位作者 毛勇建 邓婷 《振动工程学报》 EI CSCD 北大核心 2024年第10期1679-1687,共9页
提出一种主从分布式振动试验方法,建立了连续振动载荷在线复现控制技术,研制了系统样机。其中,提出一种信号分帧处理与重构技术,解决了长时连续振动载荷的在线波形复现难题;提出一种基于多量级样本库构建与加权平均的传递函数动态估计方... 提出一种主从分布式振动试验方法,建立了连续振动载荷在线复现控制技术,研制了系统样机。其中,提出一种信号分帧处理与重构技术,解决了长时连续振动载荷的在线波形复现难题;提出一种基于多量级样本库构建与加权平均的传递函数动态估计方法,抑制了系统非线性对控制精度的影响;采用谱误差反馈修正方法,改善了系统的频域控制精度。开展了“1主2从”联台试验,结果表明:时域和频域控制精度良好,整体延迟时间在亚秒量级,全程总均方根值误差在1%以内,为主从分布式振动试验提供了关键技术支撑。 展开更多
关键词 主从分布式振动试验 振动控制 在线波形复现 传递函数 分帧与重构 多量级随机信号驱动
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关于随机分布参数系统的变结构控制研究
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作者 黄邦彦 黄金花 《南京信息工程大学学报(自然科学版)》 CAS 2015年第2期184-188,共5页
研究了一类It型随机时滞分布参数系统的滑动模控制问题,设计了该系统的变结构控制器,证明了系统的滑动模运动的存在性,并分析了在滑动切换面上滑动模控制系统关于不确定量的不变性特征及运动稳定性.与相关论文相比,所获结论与扩散系... 研究了一类It型随机时滞分布参数系统的滑动模控制问题,设计了该系统的变结构控制器,证明了系统的滑动模运动的存在性,并分析了在滑动切换面上滑动模控制系统关于不确定量的不变性特征及运动稳定性.与相关论文相比,所获结论与扩散系数相关,在实际应用中更具实践意义.运用文中方法,类似论文结论均可进行改进. 展开更多
关键词 随机驱动 分布参数 变结构控制 扩散系数
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基于事件驱动的容积卡尔曼滤波定位算法 被引量:4
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作者 林浩申 李思嘉 刘刚 《中国空间科学技术》 EI CSCD 北大核心 2018年第4期11-19,共9页
以网络化非线性滤波系统为研究对象,为了平衡系统的通信率和滤波精度之间的矛盾,引入随机事件驱动(stochastic event-triggered)的思想,并在此基础上建立了基于残差检测的事件驱动(detected event-triggered)模型。针对系统的强非线性,... 以网络化非线性滤波系统为研究对象,为了平衡系统的通信率和滤波精度之间的矛盾,引入随机事件驱动(stochastic event-triggered)的思想,并在此基础上建立了基于残差检测的事件驱动(detected event-triggered)模型。针对系统的强非线性,将线性随机事件驱动滤波系统中的更新结论推广至非线性系统,推导了两种事件驱动机制在容积卡尔曼滤波(CKF)算法框架中的滤波更新过程,得到了检测事件驱动CKF(DECKF)和随机事件驱动CKF(SECKF)两种算法。最后,通过天基平台空间目标跟踪问题对算法性能进行检验。仿真结果表明,当通信率下降20.64%时,DECKF算法的位置跟踪精度和速度跟踪精度相比标准CKF仅下降了5.50%和7.74%。此外,在通信率相同的情形下,DECKF比SECKF的精度高40%以上,证明检测事件驱动模式优于随机事件驱动模式。 展开更多
关键词 网络化状态估计 随机事件驱动 检测事件驱动 容积卡尔曼滤波 空间目标跟踪
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基于改进STD法的望远镜塔架动态特性研究 被引量:1
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作者 杜福嘉 李朋辉 《机械设计》 CSCD 北大核心 2019年第1期91-95,共5页
为了精确得到某南极天文望远镜塔架的模态参数,为塔架的动力学修改和主动控制减振提供依据,按一点激励、多点加速度响应对望远镜塔架进行了锤击法模态试验。为了消除STD法数据前处理带来的噪声误差,采用改进STD法对塔架进行模态识别,用... 为了精确得到某南极天文望远镜塔架的模态参数,为塔架的动力学修改和主动控制减振提供依据,按一点激励、多点加速度响应对望远镜塔架进行了锤击法模态试验。为了消除STD法数据前处理带来的噪声误差,采用改进STD法对塔架进行模态识别,用损失函数法和极点稳态图确定模型阶次,并用实测的功率谱密度验证了所识别模态参数的准确性,在0~100 Hz的频带范围内,误差减少到了3.6%,与常规STD法相比,改进STD法明显提高了模态参数的识别精度。分析结果表明,望远镜塔架第3阶和第4阶的模态阻尼比相对较小,为塔架的薄弱频率,此结果可以作为动力学修改和望远镜主动控制减振系统调试的依据。 展开更多
关键词 改进STD法 随机驱动子空间法 模态识别 极点稳态图 功率谱密度
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随机事件驱动通信的网络化系统最优估计与状态反馈控制 被引量:6
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作者 祝超群 杨彬 +1 位作者 鲁春燕 王志文 《信息与控制》 CSCD 北大核心 2015年第6期654-659,666,共7页
针对随机事件驱动通信的网络化控制系统,研究其中的最优估计与状态反馈控制器的设计问题.首先,根据控制器与执行器/传感器的随机通信机制将系统建模为马尔可夫线性跳变系统;其次,利用时变卡尔曼滤波理论进行了系统状态估计,进而基于动... 针对随机事件驱动通信的网络化控制系统,研究其中的最优估计与状态反馈控制器的设计问题.首先,根据控制器与执行器/传感器的随机通信机制将系统建模为马尔可夫线性跳变系统;其次,利用时变卡尔曼滤波理论进行了系统状态估计,进而基于动态规划及马尔可夫跳变系统理论设计了满足二次型性能指标的最优控制器,实现了网络化系统的镇定控制;最后,通过仿真验证了所提出方法的正确性和有效性. 展开更多
关键词 随机事件驱动 网络化系统 马尔可夫链 最优估计 状态反馈
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R-dPSO算法及其在ATO控制策略中的应用 被引量:5
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作者 胡震 邹德旋 张旭 《计算机工程与应用》 CSCD 北大核心 2018年第24期212-220,226,共10页
城市轨道交通列车自动运行中,通过调整列车的5种工况序列解决含有安全、准点、准时、舒适度和能耗等指标的多目标优化问题。根据轨道交通列车自动运行过程中涉及的动力学公式建立ATO目标速度曲线的数学模型。提出一种随机驱动的全局粒... 城市轨道交通列车自动运行中,通过调整列车的5种工况序列解决含有安全、准点、准时、舒适度和能耗等指标的多目标优化问题。根据轨道交通列车自动运行过程中涉及的动力学公式建立ATO目标速度曲线的数学模型。提出一种随机驱动的全局粒子群优化算法(R-dPSO),用12个基准函数测试了R-dPSO算法的有效性。进而,利用SPSO算法、XEPSO算法和R-dPSO算法解决上述多目标优化问题。实验表明,只有R-dPSO算法的优化结果满足ATO控制策略的各个指标要求。 展开更多
关键词 工况序列 速度曲线 粒子群优化算法 随机驱动
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可加Lévy噪声驱动随机微分方程的强Feller性与指数遍历性
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作者 梁明杰 王健 《应用数学学报》 CSCD 北大核心 2017年第2期267-278,共12页
在假定Lévy过程可表示成相互独立从属布朗运动和某个Lévy过程相加的条件下,我们得到该可加Lévy噪声驱动的随机微分方程的强Feller性与指数遍历性.
关键词 Levy过程驱动随机微分方程 强Feller性 指数遍历性 从属布朗运动 耦合性
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Appearance of Stochastic Resonance in Protein Motor System
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作者 LI Jing-Hui 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第5期861-864,共4页
A protein motor system driven by sine electric field is investigated. The signal-to-noise ratio (SNR) is derived in the adiabatic limit. The phenomenon of stochastic resonance is found for this protein motor system.
关键词 stochastic resonance protein motor
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Multiplicative Stochastic Resonance for a Linear System Driven by O-U Noise
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作者 LI Jing-Hui 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第4期675-678,共4页
In the paper, we study a linear system driven by O-U noise and give a method which is different from the one stated in Europhys. Lett. 40 (1997) 117. We find the same phenomenon of multiplicative stochastic resonanc... In the paper, we study a linear system driven by O-U noise and give a method which is different from the one stated in Europhys. Lett. 40 (1997) 117. We find the same phenomenon of multiplicative stochastic resonance for the response of the system to the signal as the one found in Europhys. Left. 40 (1997) 117. The merit of our method is that it prevents the complex formulas when making sum from n = 0 to n →∞ as in Europhys. Lett. 40 (1997) 117, which leads to the approximate results of the figures. 展开更多
关键词 stochastic resonance O-U noise
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Entropic Resonant Activation and Stochastic Resonance Driven by Non-Gaussian Noise
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作者 曾春华 王华 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第11期877-884,共8页
The transition rate and stochastic resonance (SR) of a Brownian particle moving in a confined system under the presence of entropic barriers are investigated when the system is driven by non-Gaussian noise. The expl... The transition rate and stochastic resonance (SR) of a Brownian particle moving in a confined system under the presence of entropic barriers are investigated when the system is driven by non-Gaussian noise. The explicit expressions of the transition rate and the speetrai power amplification (SPA) are obtained, respectively. The effects of the parameter q indicating the departure from the Ganssian noise and the correlation time T of the non-Gaussian noise on the transition rate and the SPA are discussed. Research results show that: (i) The transition rate as a function of the noise strength exhibits a maximum. This maximum for transition rate identifies the phenomenon of entropie resonant activation (ERA), the parameter q and the noise correlation time T weaken the ERA of the system; (ii) The curves of SPA appear a transition from one peak to double-peak, and then to one peak again as the noise correlation time T of non-Gaussian noise increases. 展开更多
关键词 non-Gaussian noise confined system entropic resonant activation stochastic resonance
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Stochastic Resonance of a Periodically Driven Bistable System with Two Different Kinds of Time Delays
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作者 ZENG Chun-Hua ZHOU Xiao-Feng +2 位作者 ZENG Qin-Huang YU Huan LI Zhi-Xiong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第11期871-875,共5页
In this paper, we study the phenomenon of stochastic resonance (SR) in a periodically driven bistable system with correlations between multiplicative and additive white noise terms when there, are two different kind... In this paper, we study the phenomenon of stochastic resonance (SR) in a periodically driven bistable system with correlations between multiplicative and additive white noise terms when there, are two different kinds of time delays existed in the deterministic and fluctuating forces, respectively. Using the small time delay approximation and the theory of signal-to-noise ratio (SNR) in the adiabatic limit, the expression of SNR is obtained. The effects of the delay time T in the deterministic force, and the delay time 8 in the fluctuating force on SNR are discussed. Based on the numerical computation, it is found that: (i) There appears a reentrant transition between one peak and two peaks and then to one peak again in the curve of SNR when the value of the time delay θ is increased. (ii) SR can be realized by tuning the time delay T or 8 with fixed noise, i.e., delay-induced stochastic resonance (DSR) exists. 展开更多
关键词 stochastic resonance time delays bistable system
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Design of small-area and high-efficiency DC-DC converter for 1 T SRAM
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作者 LEE Jae-hyung 金丽妍 +4 位作者 余忆宁 JANG Ji-hye KIM Kwang-il HA Pan-bong KIM Young-hee 《Journal of Central South University》 SCIE EI CAS 2012年第2期417-423,共7页
The direct current-direct current (DC-DC) converter is designed for 1 T static random access memory (SRAM) used in display driver integrated circuits (ICs), which consists of positive word-line voltage (VpwL),... The direct current-direct current (DC-DC) converter is designed for 1 T static random access memory (SRAM) used in display driver integrated circuits (ICs), which consists of positive word-line voltage (VpwL), negative word-line voltage (VinyL) and half-VDD voltage (VHDo) generator. To generate a process voltage temperature (PVT)-insensitive VpWL and VNWL, a set of circuits were proposed to generate reference voltages using bandgap reference current generators for respective voltage level detectors. Also, a VOWL regulator and a VNWL charge pump were proposed for a small-area and low-power design. The proposed VpwL regulator can provide a large driving current with a small area since it regulates an input voltage (VCI) from 2.5 to 3.3 V. The VmvL charge pump can be implemented as a high-efficiency circuit with a small area and low power since it can transfer pumped charges to VNWL node entirely. The DC-DC converter for 1 T SRAM were designed with 0.11 μm mixed signal process and operated well with satisfactory measurement results. 展开更多
关键词 1 T-static random access memory direct current-direct current converter positive word-line voltage negative word-line voltage half- VDb generator
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Stochastically driven vibrations of single-layered graphene sheets 被引量:5
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作者 LIU RuMeng WANG LiFeng 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第6期1103-1110,共8页
Thermal vibration of single-layered graphene sheets (SLGSs) is investigated using plate model together with the law of equi-partition of energy and the molecular dynamics (MD) method based on the condensed-phase Optim... Thermal vibration of single-layered graphene sheets (SLGSs) is investigated using plate model together with the law of equi-partition of energy and the molecular dynamics (MD) method based on the condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies (COMPASS) force field.The in-plane stiffness and Poisson ratio of SLGSs are calculated by stretching SLGSs.The effective thickness of SLGSs is obtained by the MD simulations for the thermal vibration of SLGSs through the natural frequency.The root-mean-squared (RMS) amplitudes for SLGSs of differing temperatures and boundary conditions are calculated by the MD,and are compared with the results calculated by the thin plate model together with the law of equi-partition of energy.At the center of SLGSs,the thin plate theory can predict the MD results reasonably well.For the difference of bonding structure of the edge atoms,the deviation between the MD results and plate theory becomes more readily apparent near the edges of SLGSs. 展开更多
关键词 single-layered graphene sheets thermal vibration molecular dynamics simulation RMS amplitude thin plate theory equi-partition of energy
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Successful couplings for a class of stochastic differential equations driven by Lvy processes 被引量:3
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作者 LIN HuoNan WANG Jian 《Science China Mathematics》 SCIE 2012年第8期1735-1748,共14页
By constructing proper coupling operators for the integro-differential type Markov generator, we establish the existence of a successful coupling for a class of stochastic differential equations driven by Levy process... By constructing proper coupling operators for the integro-differential type Markov generator, we establish the existence of a successful coupling for a class of stochastic differential equations driven by Levy processes. Our result implies a new Liouville theorem for space-time bounded harmonic functions with respect to the underlying Markov semigroups, and it is sharp for Ornstein-Uhlenbeck processes driven by s-stable Levy processes. 展开更多
关键词 stochastic differential equations Levy processes coupling property coupling operator Liouvilletheorem
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An L_2-theory for a class of SPDEs driven by Lévy processes
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作者 CHEN Zhen-Qing KIM KyeongHun 《Science China Mathematics》 SCIE 2012年第11期2233-2246,共14页
In this paper we present an L2-theory for a class of stochastic partial differential equations driven by Levy processes. The coefficients of the equations are random functions depending on time and space variables, an... In this paper we present an L2-theory for a class of stochastic partial differential equations driven by Levy processes. The coefficients of the equations are random functions depending on time and space variables, and no smoothness assumption of the coefficients is assumed. 展开更多
关键词 stochastic parabolic partial differential equations Levy processes L2-theory
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Ergodicity of stochastic Boussinesq equations driven by Lvy processes
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作者 ZHENG Yan HUANG JianHua 《Science China Mathematics》 SCIE 2013年第6期1195-1212,共18页
We consider a class of stochastic Boussinesq equations driven by L6vy processes and establish the uniqueness of its invariant measure. The proof is based on the progressive stopping time technique.
关键词 Boussinesq equations Levy process invariant measure ERGODICITY
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Peng's maximum principle for a stochastic control problem driven by a fractional and a standard Brownian motion 被引量:2
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作者 BUCKDAHN Rainer JING Shuai 《Science China Mathematics》 SCIE 2014年第10期2025-2042,共18页
We study a stochastic control system involving both a standard and a fractional Brownian motion with Hurst parameter less than 1/2.We apply an anticipative Girsanov transformation to transform the system into another ... We study a stochastic control system involving both a standard and a fractional Brownian motion with Hurst parameter less than 1/2.We apply an anticipative Girsanov transformation to transform the system into another one,driven only by the standard Brownian motion with coefficients depending on both the fractional Brownian motion and the standard Brownian motion.We derive a maximum principle and the associated stochastic variational inequality,which both are generalizations of the classical case. 展开更多
关键词 fractional Brownian motion stochastic control system backward stochastic differential equation variational inequality maximum principle Girsanov transformation Galtchouk-Kunita-Watanabe decomposition
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Local linear estimator for stochastic diferential equations driven by α-stable Lvy motions 被引量:2
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作者 LIN ZhengYan SONG YuPing YI JiangSheng 《Science China Mathematics》 SCIE 2014年第3期609-626,共18页
We study tile local linear estimator for tile drift coefficient of stochastic differential equations driven by α-stable Levy motions observed at discrete instants. Under regular conditions, we derive the weak consis-... We study tile local linear estimator for tile drift coefficient of stochastic differential equations driven by α-stable Levy motions observed at discrete instants. Under regular conditions, we derive the weak consis- tency and central limit theorem of the estimator. Compared with Nadaraya-Watson estimator, the local linear estimator has a bias reduction whether the kernel function is symmetric or not under different schemes. A silnu- lation study demonstrates that the local linear estimator performs better than Nadaraya-Watson estimator, especially on the boundary. 展开更多
关键词 local linear estimator stable Levy motion drift coefficient bias reduction CONSISTENCY centrallimit theorem
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