期刊文献+
共找到104篇文章
< 1 2 6 >
每页显示 20 50 100
Time Parameter Based Low-Energy Data Encryption Method for Mobile Applications
1
作者 Li-Woei Chen Kun-Lin Tsai +2 位作者 Fang-Yie Leu Wen-Cheng Jiang Shih-Ting Tseng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第9期2779-2794,共16页
Various mobile devices and applications are now used in daily life.These devices require high-speed data processing,low energy consumption,low communication latency,and secure data transmission,especially in 5G and 6G... Various mobile devices and applications are now used in daily life.These devices require high-speed data processing,low energy consumption,low communication latency,and secure data transmission,especially in 5G and 6G mobile networks.High-security cryptography guarantees that essential data can be transmitted securely;however,it increases energy consumption and reduces data processing speed.Therefore,this study proposes a low-energy data encryption(LEDE)algorithm based on the Advanced Encryption Standard(AES)for improving data transmission security and reducing the energy consumption of encryption in Internet-of-Things(IoT)devices.In the proposed LEDE algorithm,the system time parameter is employed to create a dynamic S-Box to replace the static S-Box of AES.Tests indicated that six-round LEDE encryption achieves the same security level as 10-round conventional AES encryption.This reduction in encryption time results in the LEDE algorithm having a 67.4%lower energy consumption and 43.9%shorter encryption time than conventional AES;thus,the proposed LEDE algorithm can improve the performance and the energy consumption of IoT edge devices. 展开更多
关键词 Mobile application security AES data encryption time parameter mobile device
在线阅读 下载PDF
Adaptive Iterative Learning Control for Nonlinearly Parameterized Systems with Unknown Time-varying Delay and Unknown Control Direction 被引量:13
2
作者 Dan Li Jun-Min Li Department of Mathematics,Xidian University,Xi an 710071,China 《International Journal of Automation and computing》 EI 2012年第6期578-586,共9页
This paper proposes a new adaptive iterative learning control approach for a class of nonlinearly parameterized systems with unknown time-varying delay and unknown control direction.By employing the parameter separati... This paper proposes a new adaptive iterative learning control approach for a class of nonlinearly parameterized systems with unknown time-varying delay and unknown control direction.By employing the parameter separation technique and signal replacement mechanism,the approach can overcome unknown time-varying parameters and unknown time-varying delay of the nonlinear systems.By incorporating a Nussbaum-type function,the proposed approach can deal with the unknown control direction of the nonlinear systems.Based on a Lyapunov-Krasovskii-like composite energy function,the convergence of tracking error sequence is achieved in the iteration domain.Finally,two simulation examples are provided to illustrate the feasibility of the proposed control method. 展开更多
关键词 Nonlinearly time-varying parameterized systems unknown time-varying delay unknown control direction composite energy function adaptive iterative learning control.
原文传递
A tentative model for the explanation of B?th law using the order parameter of seismicity in natural time 被引量:1
3
作者 Konstantina A. Papadopoulou Efthimios S. Skordas Nicholas V. Sarlis 《Earthquake Science》 CSCD 2016年第6期311-319,共9页
Using the order parameter of seismicity defined in natural time, we suggest a simple model for the expla- nation of Bath law, according to which a mainshock differs in magnitude from its largest aftershock by approxim... Using the order parameter of seismicity defined in natural time, we suggest a simple model for the expla- nation of Bath law, according to which a mainshock differs in magnitude from its largest aftershock by approximately 1.2 regardless of the mainshock magnitude. In addition, the validity of Bath law is studied in the Global Centroid Moment Tensor catalogue by using two different aftershock definitions. It is found that the mean of this difference, when considering all the pairs mainshock-largest aftershock, does not markedly differ from 1.2 and the corresponding distributions do not depend on the mainshock's magnitude threshold in a statistically significant manner. Finally, the analysis of the cumulative distribution functions provides evidence in favour of the proposed model. 展开更多
关键词 Bath law . Aftershocks .Order parameter .Natural time
在线阅读 下载PDF
Parameterized time-frequency analysis to separate multi-radar signals 被引量:1
4
作者 Wenlong Lu Junwei Xie +1 位作者 Heming Wang Chuan Sheng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第3期493-502,共10页
Multi-radar signal separation is a critical process in modern reconnaissance systems. However, the complicated battlefield is typically confronted with increasing electronic equipment and complex radar waveforms. The ... Multi-radar signal separation is a critical process in modern reconnaissance systems. However, the complicated battlefield is typically confronted with increasing electronic equipment and complex radar waveforms. The intercepted signal is difficult to separate with conventional parameters because of severe overlapping in both time and frequency domains. On the contrary, time-frequency analysis maps the 1D signal into a 2D time-frequency plane, which provides a better insight into the signal than traditional methods. Particularly, the parameterized time-frequency analysis (PTFA) shows great potential in processing such non stationary signals. Five procedures for the PTFA are proposed to separate the overlapped multi-radar signal, including initiation, instantaneous frequency estimation with PTFA, signal demodulation, signal separation with adaptive filter and signal recovery. The proposed method is verified with both simulated and real signals, which shows good performance in the application on multi-radar signal separation. 展开更多
关键词 intercepted multi-radar signal parameterized time-frequency analysis DEMODULATION adaptive filtering
在线阅读 下载PDF
LMS-LIKE ESTIMATION FOR TIME VARYING PARAMETERS
5
作者 陈翰馥 郭雷 张纪峰 《Acta Mathematica Scientia》 SCIE CSCD 1991年第3期327-340,共14页
An LMS-like algorithm is applied for estimating the time-varying parameter theta-n in the linear model y(n) = phi-n-tau-theta-n + upsilon-n, which is general in the sense that none of the probabilistic properties such... An LMS-like algorithm is applied for estimating the time-varying parameter theta-n in the linear model y(n) = phi-n-tau-theta-n + upsilon-n, which is general in the sense that none of the probabilistic properties such as stationarity, Markov property, independence and ergodicity is imposed on any of the processes {y(n)}, {phi-n}, {theta-n} and {upsilon-n}. It is shown that the alpha-th moment of the estimation error is of order of the alpha-th moment of the observation noise and the parameter variation w(n) change in equivalence theta-n - theta-n-1. 展开更多
关键词 LMS-LIKE ESTIMATION FOR time VARYING parameterS der Zhang ACTA 石蕊 少司
在线阅读 下载PDF
TIME DOMAIN PARAMETERS IDENTIFICATION OF FOUNDATION-STRUCTURE INTERACTION SYSTEM
6
作者 黄义 刘增荣 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第7期855-864,共10页
The time domain parameter laenuncauon memoa oi me iounuauon-structure interaction system is presented. On the basis of building the computation mode and the motion equation of the foundation-structure interaction syst... The time domain parameter laenuncauon memoa oi me iounuauon-structure interaction system is presented. On the basis of building the computation mode and the motion equation of the foundation-structure interaction system, the system parameter identification method was established by using the extended Kalman filter (EKF) technique and taking the unknown parameters in the system as the augment state variables. And the time parameter identification process of the foundation-structure interaction system was implemented by using the data of the layer foundation-storehouse interaction system model test on the large vibration platform. The computation result shows that the established parameter identification method can induce good parameter estimation. 展开更多
关键词 foundation-structure interaction system time domain parameter identification
在线阅读 下载PDF
Performance analysis model for real-time Ethernet-based computer numerical control system 被引量:2
7
作者 万加富 李迪 +1 位作者 涂钰青 张春华 《Journal of Central South University》 SCIE EI CAS 2011年第5期1545-1553,共9页
In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign met... In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethemet, system architecture, time characteristic parameters of control-loop ere, a performance analysis model for real-time Ethemet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development. 展开更多
关键词 computer numerical control (CNC) system real-time Ethemet time characteristic parameters performance analysis model manufacturing accuracy
在线阅读 下载PDF
Time variant multi-objective linear fractional interval-valued transportation problem 被引量:1
8
作者 Dharmadas Mardanya Sankar Kumar Roy 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2022年第1期111-130,共20页
This paper studies a time-variant multi-objective linear fractional transportation problem. In reality, transported goods should reach in destinations within a specific time. Considering the importance of time, a time... This paper studies a time-variant multi-objective linear fractional transportation problem. In reality, transported goods should reach in destinations within a specific time. Considering the importance of time, a time-variant multi-objective linear fractional transportation problem is formulated here. We take into account the parameters as cost, supply and demand are interval valued that involved in the proposed model, so we treat the model as a multi-objective linear fractional interval transportation problem. To solve the formulated model, we first convert it into a deterministic form using a new transformation technique and then apply fuzzy programming to solve it. The applicability of our proposed method is shown by considering two numerical examples. At last, conclusions and future research directions regarding our study is included. 展开更多
关键词 fractional transportation problem multi-objective optimization interval number time variant parameter fuzzy programming Pareto optimal solution
在线阅读 下载PDF
Novel l_2-l_∞ controller design for LPV discrete time-delay systems 被引量:1
9
作者 WangJunling WangChanghong LiYanhui GaoHuijun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第1期128-133,共6页
One of the first attempts to derive energy-to-peak performance criteria and state-feedback controller design problem for linear parameter-varying discrete time systems with time delay is provided. Firstly, we present ... One of the first attempts to derive energy-to-peak performance criteria and state-feedback controller design problem for linear parameter-varying discrete time systems with time delay is provided. Firstly, we present a parameter-dependent l 2-l ∞ performance criterion using a parameter-dependent Lyapunov function. Upon the conditions addressed, an improved parameter-dependent l 2-l ∞ performance criterion is established by the introduction of a slack variable, which exhibits a kind of decoupling between Lyapunov functions and system matrices. This kind of decoupling enables us to obtain more easily tractable conditions for analysis and synthesis problems. Then, the corresponding parameter-dependent state-feedback controller design is investigated upon these performance criteria, with sufficient conditions obtained for the existence of admissible controllers in terms of parameterized linear matrix inequalities. Finally, a numerical example is provided to illustrate the feasibility and advantage of the proposed controller design procedure. 展开更多
关键词 linear parameter-varying discrete-time system parameterized linear matrix inequality time delay l 2-l control.
在线阅读 下载PDF
Observer-based Adaptive Iterative Learning Control for Nonlinear Systems with Time-varying Delays 被引量:10
10
作者 Wei-Sheng Chen Rui-Hong Li Jing Li 《International Journal of Automation and computing》 EI 2010年第4期438-446,共9页
An observer-based adaptive iterative learning control (AILC) scheme is developed for a class of nonlinear systems with unknown time-varying parameters and unknown time-varying delays. The linear matrix inequality (... An observer-based adaptive iterative learning control (AILC) scheme is developed for a class of nonlinear systems with unknown time-varying parameters and unknown time-varying delays. The linear matrix inequality (LMI) method is employed to design the nonlinear observer. The designed controller contains a proportional-integral-derivative (PID) feedback term in time domain. The learning law of unknown constant parameter is differential-difference-type, and the learning law of unknown time-varying parameter is difference-type. It is assumed that the unknown delay-dependent uncertainty is nonlinearly parameterized. By constructing a Lyapunov-Krasovskii-like composite energy function (CEF), we prove the boundedness of all closed-loop signals and the convergence of tracking error. A simulation example is provided to illustrate the effectiveness of the control algorithm proposed in this paper. 展开更多
关键词 Adaptive iterative learning control (AILC) nonlinearly parameterized systems time-varying delays Lyapunov- Krasovskii-like composite energy function.
在线阅读 下载PDF
Push-Pull Finite-Time Convergence Distributed Optimization Algorithm 被引量:1
11
作者 Xiaobiao Chen Kaixin Yan +3 位作者 Yu Gao Xuefeng Xu Kang Yan Jing Wang 《American Journal of Computational Mathematics》 2020年第1期118-146,共29页
With the widespread application of distributed systems, many problems need to be solved urgently. How to design distributed optimization strategies has become a research hotspot. This article focuses on the solution r... With the widespread application of distributed systems, many problems need to be solved urgently. How to design distributed optimization strategies has become a research hotspot. This article focuses on the solution rate of the distributed convex optimization algorithm. Each agent in the network has its own convex cost function. We consider a gradient-based distributed method and use a push-pull gradient algorithm to minimize the total cost function. Inspired by the current multi-agent consensus cooperation protocol for distributed convex optimization algorithm, a distributed convex optimization algorithm with finite time convergence is proposed and studied. In the end, based on a fixed undirected distributed network topology, a fast convergent distributed cooperative learning method based on a linear parameterized neural network is proposed, which is different from the existing distributed convex optimization algorithms that can achieve exponential convergence. The algorithm can achieve finite-time convergence. The convergence of the algorithm can be guaranteed by the Lyapunov method. The corresponding simulation examples also show the effectiveness of the algorithm intuitively. Compared with other algorithms, this algorithm is competitive. 展开更多
关键词 DISTRIBUTED Optimization FINITE time CONVERGENCE Linear parameterized NEURAL Network PUSH-PULL Algorithm Undirected Graph
在线阅读 下载PDF
Ehrenfest Approach to the Adiabatic Invariants and Calculation of the Intervals of Time Entering the Energy Emission Process in Simple Quantum Systems 被引量:1
12
作者 Stanislaw Olszewski 《Journal of Quantum Information Science》 2020年第1期1-9,共9页
In the first step, the Ehrenfest reasoning concerning the adiabatic invariance of the angular orbital momentum is applied to the electron motion in the hydrogen atom. It is demonstrated that the time of the energy emi... In the first step, the Ehrenfest reasoning concerning the adiabatic invariance of the angular orbital momentum is applied to the electron motion in the hydrogen atom. It is demonstrated that the time of the energy emission from the quantum level n+1 to level n can be deduced from the orbital angular momentum examined in the hydrogen atom. This time is found precisely equal to the time interval dictated by the Joule-Lenz law governing the electron transition between the levels n+1 and n. In the next step, the mechanical parameters entering the quantum systems are applied in calculating the time intervals characteristic for the electron transitions. This concerns the neighbouring energy levels in the hydrogen atom as well as the Landau levels in the electron gas submitted to the action of a constant magnetic field. 展开更多
关键词 Aadiabatic Invariants time of the Energy Emission Process Referred to the Mechanical parameters of a Quantum System Hydrogen Atom The Landau Levels in the Electron Gas
在线阅读 下载PDF
基于PMSST的风电系统次同步振荡检测
13
作者 刘志坚 唐程 +2 位作者 李瑞欣 董航 陈继开 《电力科学与技术学报》 北大核心 2025年第5期130-142,共13页
近年来,风力发电的迅速发展使电力系统运行状态日益复杂,次同步振荡(sub-synchronous oscillation,SSO)发生的风险显著增加。准确且快速地检测SSO的存在对于制定有效的抑制措施至关重要。然而,现有检测方法普遍存在噪声适应性差和模态... 近年来,风力发电的迅速发展使电力系统运行状态日益复杂,次同步振荡(sub-synchronous oscillation,SSO)发生的风险显著增加。准确且快速地检测SSO的存在对于制定有效的抑制措施至关重要。然而,现有检测方法普遍存在噪声适应性差和模态堆叠等问题。为此,提出了一种新的检测方法,即基于加权最小二乘法、多重同步压缩变换与多项式啁啾变换相结合的参数化多同步压缩变换(parameterized multi-synchrosqueezing transform,PMSST)方法。在PMSST方法中,首先采用多重同步压缩变换获得具有高能量聚集特性的信号时频表示;然后,通过脊线提取算法提取各单分量信号的瞬时频率脊线,并利用加权最小二乘法对参数化变换核的参数进行估计;最后,重构时频谱以得到增强后的信号时频能量表示,并结合旋转不变技术进行参数辨识。仿真结果表明,基于数字仿真信号及双馈风力发电机模拟的SSO信号,PMSST方法能够有效抑制噪声干扰,实现更准确的SSO信号分解,并具有较高的参数辨识可靠性。 展开更多
关键词 次同步振荡 多项式啁啾变换 参数识别 参数化多重压缩变换 时频分析
在线阅读 下载PDF
数据驱动的船舶动力冷凝器系统容错控制策略研究
14
作者 王豪 李献领 +3 位作者 宁哲远 乔新宇 蒋宇辰 罗浩 《热能动力工程》 北大核心 2025年第6期101-109,共9页
随着船舶动力系统智能化和自动化水平的提升,其复杂性和故障率显著增加,对安全性和可靠性提出了更高要求。针对传统容错控制方法依赖精确模型的局限性,提出了一种基于Youla参数化的数据驱动容错控制方法,通过自适应观测器实时辨识冷凝... 随着船舶动力系统智能化和自动化水平的提升,其复杂性和故障率显著增加,对安全性和可靠性提出了更高要求。针对传统容错控制方法依赖精确模型的局限性,提出了一种基于Youla参数化的数据驱动容错控制方法,通过自适应观测器实时辨识冷凝器的系统参数,并利用残差驱动的Youla参数化控制器进行在线参数学习,实现了控制性能的实时优化与容错控制。仿真结果表明:进行容错控制后水位的跟踪误差较没有进行容错控制减小约50%,说明所提方法能够有效进行容错控制并显著提高冷凝器系统的可靠性。 展开更多
关键词 船舶动力冷凝器系统 故障诊断 容错控制 数据驱动 实时优化 YOULA参数化
原文传递
基于结构重参数化和共享卷积的实时工业缺陷检测方法
15
作者 苏源 孙丹枫 +1 位作者 赵建勇 巫宝军 《现代制造工程》 北大核心 2025年第12期83-96,共14页
针对现代工业生产中高效缺陷检测的需求,提出了一种基于结构重参数化和共享卷积的实时工业缺陷检测方法,旨在提高检测精度与推理速度,降低模型复杂度。在特征提取阶段,设计了基于部分通道卷积与结构重参数化的LRD-ELAN模块。通过重参数... 针对现代工业生产中高效缺陷检测的需求,提出了一种基于结构重参数化和共享卷积的实时工业缺陷检测方法,旨在提高检测精度与推理速度,降低模型复杂度。在特征提取阶段,设计了基于部分通道卷积与结构重参数化的LRD-ELAN模块。通过重参数化模块与可变形卷积的引入,强化特征表达能力,减少冗余计算。在检测头设计中,提出轻量化GS-Head模块,利用Ghost共享卷积降低检测头计算量,结合组归一化提升小批量训练的稳定性。此外,在边界框预测分支中引入轻量级特征缩放层,增强多尺度目标检测能力,并使用inner-MPDIoU损失函数替代传统CIoU损失函数,进一步优化边界框预测性能。试验结果表明,在NEU-DET数据集上,该模型的mAP50较基线模型提升了2.46%,参数量和计算量分别减少了37.10%和33.58%,推理帧率达286.1 FPS,提升了10.82%,具备良好的实时性。在PKU-Market-PCB数据集的泛化测试中,mAP50较基线模型提升了1.91%,表现出较强的泛化能力和高效性。该模型在速度、精度与复杂度之间实现了良好平衡,展现出在工业缺陷检测中的应用潜力与优势。 展开更多
关键词 实时缺陷检测 结构重参数化 共享卷积 组归一化 模型轻量化 损失函数
在线阅读 下载PDF
可伸缩的增量连续k近邻查询处理 被引量:10
16
作者 廖巍 熊伟 +2 位作者 王钧 景宁 钟志农 《软件学报》 EI CSCD 北大核心 2007年第2期268-278,共11页
针对基于TPR树(time-parameterized R-tree)索引的大量并发CKNN(continuous k-nearest neighbor)查询处理,提出了一种可伸缩的增量连续k近邻查询处理(scalable processing of incremental continuous k-nearest neighbor queries,简称SI... 针对基于TPR树(time-parameterized R-tree)索引的大量并发CKNN(continuous k-nearest neighbor)查询处理,提出了一种可伸缩的增量连续k近邻查询处理(scalable processing of incremental continuous k-nearest neighbor queries,简称SI-CNN)框架,通过引入搜索区域进行预裁剪以减少查询更新所需要的TPR树节点访问代价,并引入了增量结果表以保存候选对象,批量地更新查询结果集,具有良好的可伸缩性.基于SI-CNN框架提出了一种增量更新的SI-CNN查询处理算法,能够基于上次查询结果增量的更新查询,支持查询集合中加入或删除查询和移动对象数据集的插入、删除等动态更新操作.实验结果与分析表明,基于SI-CNN框架的SI-CNN算法可以很好地支持大量并发的CKNN查询处理,具有良好的实用价值. 展开更多
关键词 连续K近邻查询 TPR树 SI—CNN框架 SI—CNN算法 增量处理
在线阅读 下载PDF
翼伞系统最优归航轨迹设计的敏感度分析方法 被引量:16
17
作者 梁海燕 任志刚 +1 位作者 许超 言金 《控制理论与应用》 EI CAS CSCD 北大核心 2015年第8期1003-1011,共9页
本文对三自由度翼伞系统归航轨迹优化问题进行了研究,采用控制变量参数化与时间尺度变换相结合的优化算法对翼伞系统的最优控制问题进行数值求解.该方法是基于灵敏度分析的优化算法,将控制量以及控制量转换时间转化为一系列参数优化问... 本文对三自由度翼伞系统归航轨迹优化问题进行了研究,采用控制变量参数化与时间尺度变换相结合的优化算法对翼伞系统的最优控制问题进行数值求解.该方法是基于灵敏度分析的优化算法,将控制量以及控制量转换时间转化为一系列参数优化问题同时进行求解.仿真结果表明,相对于基于两端边值优化算法而言,灵敏度分析法只需要正向积分进行求解,因而具有计算简单、耗时短等优点,其控制效果良好,距离偏差和方向偏差均满足实际需求,有效地提高了翼伞系统的着陆精度,验证了该优化算法的可行性. 展开更多
关键词 翼伞 轨迹优化 时间尺度变换 参数化 优化 灵敏度分析
在线阅读 下载PDF
基于反应力向量灵敏度的模型参数化方法 被引量:5
18
作者 赵昕 李杰 《振动与冲击》 EI CSCD 北大核心 2002年第4期61-65,共5页
模型参数化是建立识别方程的关键。本文在虚拟结构向量转换方法的基础上提出了“基于反应力向量灵敏度的模型参数化方法”。该方法首先将反应力向量对单元物理参数作一阶展开 ,对线性参数系统来说 ,即为反应力向量灵敏度与单元物理参数... 模型参数化是建立识别方程的关键。本文在虚拟结构向量转换方法的基础上提出了“基于反应力向量灵敏度的模型参数化方法”。该方法首先将反应力向量对单元物理参数作一阶展开 ,对线性参数系统来说 ,即为反应力向量灵敏度与单元物理参数的乘积 ;其次 ,在线性参数系统的假定下 ,对一个单元中包含多个单元物理参数的情况提出了一个简便的求反应力向量灵敏度的算法。利用该方法可直接由常规的有限元代码获得反应力向量灵敏度矩阵 ,而无需编制专门的有限元代码集成分析代码。文中通过算例阐述了该方法的应用。 展开更多
关键词 反应力向量 结构识别 时域方法 灵敏度 模型参数化 虚拟结构 向量转换方法
在线阅读 下载PDF
支持高效更新的移动对象索引研究 被引量:1
19
作者 潘锦基 马廷淮 刘景发 《南京航空航天大学学报》 EI CAS CSCD 北大核心 2009年第6期748-752,共5页
基于TPR-树(Time parameterized R-tree,TPR-树)提出的LUTPR-树采用基于主存的更新方法,更新对象的删除操作在内存中完成,故避免了TPR-树中对象更新所导致的耗时的查找操作。同时,LUTPR-树能有效利用主存资源。实验结果表明,与TPR-树相... 基于TPR-树(Time parameterized R-tree,TPR-树)提出的LUTPR-树采用基于主存的更新方法,更新对象的删除操作在内存中完成,故避免了TPR-树中对象更新所导致的耗时的查找操作。同时,LUTPR-树能有效利用主存资源。实验结果表明,与TPR-树相比,LUTPR-树以牺牲很小部分查询性能为代价,大大提高了更新效率,更加适用于更新密集型应用。 展开更多
关键词 频繁更新 延迟删除 TPR-树 自底向上更新方法
在线阅读 下载PDF
周期时变时滞非线性参数化系统的自适应学习控制 被引量:26
20
作者 陈为胜 王元亮 李俊民 《自动化学报》 EI CSCD 北大核心 2008年第12期1556-1560,共5页
针对一阶未知非线性参数化周期时变时滞系统,设计了一种自适应学习控制方案。假设未知时变参数,时变时滞和参考信号的共同周期是已知的,通过重构系统方程,将包含时变时滞在内的所有未知时变项合并成为一个周期时变向量,采用周期自适应... 针对一阶未知非线性参数化周期时变时滞系统,设计了一种自适应学习控制方案。假设未知时变参数,时变时滞和参考信号的共同周期是已知的,通过重构系统方程,将包含时变时滞在内的所有未知时变项合并成为一个周期时变向量,采用周期自适应律估计该向量.通过构造一个Lyapunov—Krasovskii型复合能量函数证明了所有信号有界并且跟踪误差收敛.结果被推广到一类含有混合参数的高阶非线性系统.通过两个仿真例子说明本文所提出的控制算法的有效性. 展开更多
关键词 学习控制 非线性参数化系统 时变时滞 复合能量函数
在线阅读 下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部