期刊文献+
共找到3,879篇文章
< 1 2 194 >
每页显示 20 50 100
On asymptotic properties of a constant-step-size sign-error algorithm for adaptive filtering
1
作者 殷刚 陈翰馥 《Science in China(Series F)》 EI 2002年第5期321-334,共14页
This work is devoted to asymptotic properties of a sign-error adaptive filtering algorithm with constant step size. Under much weaker conditions than those that appear in the literature, we obtain convergence and rate... This work is devoted to asymptotic properties of a sign-error adaptive filtering algorithm with constant step size. Under much weaker conditions than those that appear in the literature, we obtain convergence and rate of convergence by using weak convergence methods. An example is provided to demonstrate the performance of the algorithm. 展开更多
关键词 sign-error algorithm constant step size weak convergence rate of convergence diffusion limit.
原文传递
PROXIMAL POINT ALGORITHM WITH ERRORS FOR GENERALIZED STRONGLY NONLINEARQUASIVARIATIONAL INCLUSIONS 被引量:1
2
作者 丁协平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第7期637-643,共7页
In this paper, a class of generalized strongly nonlinear quasivariational inclusions are studied. By using the properties of the resolvent operator associated with a maximal monotone; mapping in Hilbert space, an exis... In this paper, a class of generalized strongly nonlinear quasivariational inclusions are studied. By using the properties of the resolvent operator associated with a maximal monotone; mapping in Hilbert space, an existence theorem of solutions for generalized strongly nonlinear quasivariational inclusion is established and a new proximal point algorithm with errors is suggested for finding approximate solutions which strongly converge to the exact solution of the generalized strongly, nonlinear quasivariational inclusion. As special cases, some known results in this field are also discussed. 展开更多
关键词 generalized strongly nonlinear quasivariational inclusion proximal point algorithm with errors
下载PDF
Improved algorithm of atmospheric refraction error in Longley-Rice channel model 被引量:2
3
作者 Wang Zuliang Zheng Mao +1 位作者 Wang Juan Zheng Linhua 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第4期683-687,共5页
Longley-Rice channel model modifies the atmospheric refraction by the equivalent earth radius method, which is simple calculation but is not accurate. As it only uses the horizontal difference, but does not make use o... Longley-Rice channel model modifies the atmospheric refraction by the equivalent earth radius method, which is simple calculation but is not accurate. As it only uses the horizontal difference, but does not make use of the vertical section information, it does not agree with the actual propagation path. The atmospheric refraction error correction method of the Longley-Rice channel model has been improved. The improved method makes use of the vertical section information sufficiently and maps the distance between the receiver and transmitter to the radio wave propagation distance, It can exactly reflect the infection of propagation distance for the radio wave propagation loss. It is predicted to be more close to the experimental results by simulation in comparison with the measured data. The effectiveness of improved methods is proved by simulation. 展开更多
关键词 radio wave propagation atmospheric refraction error correction algorithm improvement Longley- Rice model.
下载PDF
MATRIX ALGORITHMS AND ERROR FORMULA FOR BIVARIATE THIELE-TYPE RECTANGULAR MATRIX VALUED RATIONAL INTERPOLATION 被引量:1
4
作者 顾传青 朱功勤 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1999年第2期195-208,共14页
A new method for the construction of bivariate matrix valued rational interpolants (BGIRI) on a rectangular grid is presented in [6]. The rational interpolants are of Thiele-type continued fraction form with scalar de... A new method for the construction of bivariate matrix valued rational interpolants (BGIRI) on a rectangular grid is presented in [6]. The rational interpolants are of Thiele-type continued fraction form with scalar denominator. The generalized inverse introduced by [3]is gen-eralized to rectangular matrix case in this paper. An exact error formula for interpolation is ob-tained, which is an extension in matrix form of bivariate scalar and vector valued rational interpola-tion discussed by Siemaszko[l2] and by Gu Chuangqing [7] respectively. By defining row and col-umn-transformation in the sense of the partial inverted differences for matrices, two type matrix algorithms are established to construct corresponding two different BGIRI, which hold for the vec-tor case and the scalar case. 展开更多
关键词 BIVARIATE MATRIX VALUED RATIONAL inter polants error FORMULA MATRIX algorithms.
下载PDF
FORM ERROR EVALUATION OF CIRCLES BASED ON A FINELY-DESIGNED GENETIC ALGORITHM 被引量:5
5
作者 CuiChangcai CheRensheng LiZhongyan YeDong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第1期59-62,共4页
A genetic algorithm(GA)-based new method is designed to evaluate thecircularity error of mechanical parts. The method uses the capability of nonlinear optimization ofGA to search for the optimal solution of circularit... A genetic algorithm(GA)-based new method is designed to evaluate thecircularity error of mechanical parts. The method uses the capability of nonlinear optimization ofGA to search for the optimal solution of circularity error. The finely-designed GA (FDGA)characterized dynamical bisexual recombination and Gaussian mutation. The mathematical model of thenonlinear problem is given. The implementation details in FDGA are described such as the crossoveror recombination mechanism which utilized a bisexual reproduction scheme and the elitist reservationmethod; and the adaptive mutation which used the Gaussian probability distribution to determine thevalues of the offspring produced by mutation mechanism. The examples are provided to verify thedesigned FDGA. The computation results indicate that the FDGA works very well in the field of formerror evaluation such as circularity evaluation. 展开更多
关键词 Genetic algorithm(GA) Form error CIRCULARITY Bisexual recombination Gaussian mutation
下载PDF
PARALLEL SCHWARZ ALGORITHMS FOR PARABOLIC EQUATIONS AND ERROR ESTIMATES
6
作者 芮洪兴 羊丹平 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1997年第1期45-56,共12页
In this paper we introduce two kinds of parallel Schwarz domain decomposition me thods for general, selfadjoint, second order parabolic equations and study the dependence of their convergence rates on parameters of ti... In this paper we introduce two kinds of parallel Schwarz domain decomposition me thods for general, selfadjoint, second order parabolic equations and study the dependence of their convergence rates on parameters of time-step and space-mesh. We prove that the, approximate solution has convergence independent of iteration times at each time-level. And the L^2 error estimates are given. 展开更多
关键词 SCHWARZ algorithms PARABOLIC equations domain decomposition error ESTIMATES PARALLEL algorithm.
下载PDF
Geometric Approximation Searching Algorithm for Spatial Straightness Error Evaluation 被引量:1
7
作者 Jishun Li Xianqing Lei +1 位作者 Yujun Xue Weimin Pan 《Modern Instrumentation》 2013年第1期1-6,共6页
Considering the characteristics of spatial straightness error, this paper puts forward a kind of evaluation method of spatial straightness error using Geometric Approximation Searching Algorithm (GASA). According to t... Considering the characteristics of spatial straightness error, this paper puts forward a kind of evaluation method of spatial straightness error using Geometric Approximation Searching Algorithm (GASA). According to the minimum condition principle of form error evaluation, the mathematic model and optimization objective of the GASA are given. The algorithm avoids the optimization and linearization, and can be fulfilled in three steps. First construct two parallel quadrates based on the preset two reference points of the spatial line respectively;second construct centerlines by connecting one quadrate each vertices to another quadrate each vertices;after that, calculate the distances between measured points and the constructed centerlines. The minimum zone straightness error is obtained by repeating comparing and reconstructing quadrates. The principle and steps of the algorithm to evaluate spatial straightness error is described in detail, and the mathematical formula and program flowchart are given also. Results show that this algorithm can evaluate spatial straightness error more effectively and exactly. 展开更多
关键词 error Evaluation Spatial STRAIGHTNESS GEOMETRIC APPROXIMATION SEARCHING algorithm Minimum ZONE
下载PDF
ANN model of subdivision error based on genetic algorithm
8
作者 齐明 邹继斌 尚静 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2010年第1期131-136,共6页
According to the test data of subdivision errors in the measuring cycle of angular measuring system, the characteristics of subdivision errors generated by this system are analyzed. It is found that the subdivision er... According to the test data of subdivision errors in the measuring cycle of angular measuring system, the characteristics of subdivision errors generated by this system are analyzed. It is found that the subdivision errors are mainly due to the rotary-type inductosyn itself. For the characteristic of cyclical change, the subdivision errors in other measuring cycles can be compensated by the subdivision error model in one measuring cycle. Using the measured error data as training samples, combining GA and BP algorithm, an ANN model of subdivision error is designed. Simulation results indicate that GA reduces the uncertainty in the training process of the ANN model, and enhances the generalization of the model. Compared with the error model based on the least-mean-squared method, the designed ANN model of subdivision errors can achieve higher compensating precision. 展开更多
关键词 genetic algorithm artificial neural network (ANN) subdivision error angular measuring system error model
下载PDF
Effects of systematic phase errors on optimized quantum random-walk search algorithm
9
作者 张宇超 鲍皖苏 +1 位作者 汪翔 付向群 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第6期155-163,共9页
This study investigates the effects of systematic errors in phase inversions on the success rate and number of iterations in the optimized quantum random-walk search algorithm. Using the geometric description of this ... This study investigates the effects of systematic errors in phase inversions on the success rate and number of iterations in the optimized quantum random-walk search algorithm. Using the geometric description of this algorithm, a model of the algorithm with phase errors is established, and the relationship between the success rate of the algorithm, the database size, the number of iterations, and the phase error is determined. For a given database size, we obtain both the maximum success rate of the algorithm and the required number of iterations when phase errors are present in the algorithm. Analyses and numerical simulations show that the optimized quantum random-walk search algorithm is more robust against phase errors than Grover's algorithm. 展开更多
关键词 quantum search algorithm quantum random walk phase errors ROBUSTNESS
下载PDF
Error Analysis in Frequency Domain for Linear Multipass Algorithms
10
作者 费景高 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2001年第4期77-84,共8页
Error analysis methods in frequency domain are developed in this paper for determining the characteristic root and transfer function errors when the linear multipass algorithms are used to solve linear differential eq... Error analysis methods in frequency domain are developed in this paper for determining the characteristic root and transfer function errors when the linear multipass algorithms are used to solve linear differential equations. The relation between the local truncation error in time domain and the error in frequency domain is established, which is the basis for developing the error estimation methods. The error estimation methods for the digital simulation model constructed by using the Runge-Kutta algorithms and the linear multistep predictor-corrector algorithms are also given. 展开更多
关键词 algorithmS Computer simulation Differential equations error analysis Frequency domain analysis Runge Kutta methods
下载PDF
Application of Genetic Algorithm in Estimation of Gyro Drift Error Model 被引量:1
11
作者 LI Dongmei BAI Taixun +1 位作者 HE Xiaoxia ZHANG Rong 《Aerospace China》 2019年第1期3-8,共6页
Extended Kalman Filter(EKF)algorithm is widely used in parameter estimation for nonlinear systems.The estimation precision is sensitively dependent on EKF’s initial state covariance matrix and state noise matrix.The ... Extended Kalman Filter(EKF)algorithm is widely used in parameter estimation for nonlinear systems.The estimation precision is sensitively dependent on EKF’s initial state covariance matrix and state noise matrix.The grid optimization method is always used to find proper initial matrix for off-line estimation.However,the grid method has the draw back being time consuming hence,coarse grid followed by a fine grid method is adopted.To further improve efficiency without the loss of estimation accuracy,we propose a genetic algorithm for the coarse grid optimization in this paper.It is recognized that the crossover rate and mutation rate are the main influencing factors for the performance of the genetic algorithm,so sensitivity experiments for these two factors are carried out and a set of genetic algorithm parameters with good adaptability were selected by testing with several gyros’experimental data.Experimental results show that the proposed algorithm has higher efficiency and better estimation accuracy than the traversing grid algorithm. 展开更多
关键词 genetic algorithm traversing GRID algorithm coarse GRID optimization GYRO DRIFT error model CROSSOVER RATE and mutation RATE selecting
下载PDF
Wireless location algorithm using digital broadcasting signals based on neural network 被引量:1
12
作者 柯炜 吴乐南 殷奎喜 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期394-398,共5页
In order to enhance the accuracy and reliability of wireless location under non-line-of-sight (NLOS) environments,a novel neural network (NN) location approach using the digital broadcasting signals is presented. ... In order to enhance the accuracy and reliability of wireless location under non-line-of-sight (NLOS) environments,a novel neural network (NN) location approach using the digital broadcasting signals is presented. By the learning ability of the NN and the closely approximate unknown function to any degree of desired accuracy,the input-output mapping relationship between coordinates and the measurement data of time of arrival (TOA) and time difference of arrival (TDOA) is established. A real-time learning algorithm based on the extended Kalman filter (EKF) is used to train the multilayer perceptron (MLP) network by treating the linkweights of a network as the states of the nonlinear dynamic system. Since the EKF-based learning algorithm approximately gives the minimum variance estimate of the linkweights,the convergence is improved in comparison with the backwards error propagation (BP) algorithm. Numerical results illustrate thatthe proposedalgorithmcanachieve enhanced accuracy,and the performance ofthe algorithmis betterthanthat of the BP-based NN algorithm and the least squares (LS) algorithm in the NLOS environments. Moreover,this location method does not depend on a particular distribution of the NLOS error and does not need line-of-sight ( LOS ) or NLOS identification. 展开更多
关键词 digital broadcasting signals neural network extended Kalman filter (EKF) backwards error propagation algorithm multilayer perceptron
下载PDF
一种二阶TD Error快速Q(λ)算法 被引量:5
13
作者 傅启明 刘全 +3 位作者 孙洪坤 高龙 李瑾 王辉 《模式识别与人工智能》 EI CSCD 北大核心 2013年第3期282-292,共11页
Q(λ)学习算法是一种结合值迭代与随机逼近的思想的基于模型无关的多步离策略强化学习算法.针对经典的Q(λ)学习算法执行效率低、收敛速度慢的问题,从TD Error的角度出发,给出n阶TD Error的概念,并将n阶TD Error用于经典的Q(λ)学习算法... Q(λ)学习算法是一种结合值迭代与随机逼近的思想的基于模型无关的多步离策略强化学习算法.针对经典的Q(λ)学习算法执行效率低、收敛速度慢的问题,从TD Error的角度出发,给出n阶TD Error的概念,并将n阶TD Error用于经典的Q(λ)学习算法,提出一种二阶TD Error快速Q(λ)学习算法——SOE-FQ(λ)算法.该算法利用二阶TD Error修正Q值函数,并通过资格迹将TD Error传播至整个状态动作空间,加快算法的收敛速度.在此基础之上,分析算法的收敛性及收敛效率,在仅考虑一步更新的情况下,算法所要执行的迭代次数T主要指数依赖于1/1-γ、1/ε.将SOE-FQ(λ)算法用于Random Walk和Mountain Car问题,实验结果表明,算法具有较快的收敛速度和较好的收敛精度. 展开更多
关键词 强化学习 马尔科夫决策过程 二阶TD error 资格迹 Q(λ)算法
下载PDF
Errors-in-variables模型的参数估计 被引量:3
14
作者 时正华 袁永生 《曲阜师范大学学报(自然科学版)》 CAS 2005年第1期35-37,共3页
介绍了Errors_in_variables模型 ,利用Fisher得分算法 ,给出了在自变量的随机影响因素和因变量的随机影响因素相互独立和无重复测量数据情况下Errors_in_variables模型参数估计的迭代公式 .
关键词 随机自变量 errors-in-variables模型 Fisher得分算法
下载PDF
Routing Protocol Based on Grover’s Searching Algorithm for Mobile Ad-hoc Networks 被引量:3
15
作者 孟利民 宋文波 《China Communications》 SCIE CSCD 2013年第3期145-156,共12页
In Mobile Ad-hoc Networks (MANETs), routing protocols directly affect various indices of network Quality of Service (QoS), so they play an important role in network performance. To address the drawbacks associated wit... In Mobile Ad-hoc Networks (MANETs), routing protocols directly affect various indices of network Quality of Service (QoS), so they play an important role in network performance. To address the drawbacks associated with traditional routing protocols in MANETs, such as poor anti-fading performance and slow convergence rate, for basic Dynamic Source Routing (DSR), we propose a new routing model based on Grover's searching algorithm. With this new routing model, each node maintains a node vector function, and all the nodes can obtain a node probability vector using Grover's algorithm, and then select an optimal routing according to node probability. Simulation results show that compared with DSR, this new routing protocol can effectively extend the network lifetime, as well as reduce the network delay and the number of routing hops. It can also significantly improve the anti-jamming capability of the network. 展开更多
关键词 Grover's channel fading additive bit error rate searching algorithm noise network delay
下载PDF
Influence Analysis of Machining and Installation Errors on the Radial Stiffness of a Non-Pneumatic Mechanical Elastic Wheel 被引量:2
16
作者 You-Qun Zhao Zhen Xiao +2 位作者 Fen Lin Ming-Min Zhu Yao-Ji Deng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第4期92-100,共9页
Machining and installation errors are unavoidable in mechanical structures. However, the effect of errors on radial stiffness of the mechanical elastic wheel(ME-Wheel) is not considered in previous studies. To this en... Machining and installation errors are unavoidable in mechanical structures. However, the effect of errors on radial stiffness of the mechanical elastic wheel(ME-Wheel) is not considered in previous studies. To this end, the interval mathematical model and interval finite element model of the ME-Wheel were both established and compared with bench test results. The intercomparison of the influence of the machining and installation errors on the ME-Wheel radial stiffness revealed good consistency among the interval mathematical analysis, interval finite element simulation,and bench test results. Within the interval range of the ME-Wheel machining and installation errors, parametric analysis of the combined elastic rings was performed at different initial radial rigidity values. The results showed that the initial radial stiffness of the flexible tire body significantly influenced the ME-Wheel radial stiffness, and the inverse relationship between the hinge unit length or suspension hub and the radial stiffness was nonlinear. The radial stiffness of the ME-Wheel is predicted by using the interval algorithm for the first time, and the regularity of the radial stiffness between the error and the load on the ME-Wheel is studied, which will lay the foundation for the exact study of the ME-Wheel dynamic characteristics in the future. 展开更多
关键词 Mechanical elastic wheel Stiffness characteristic errorS Interval algorithm Interval finite element
下载PDF
ON THE EQUIVALENCE OF PDA ALGORITHM AND SIC-MMSE ALGORITHM 被引量:3
17
作者 Li Xiaofei Mei Zhonghui 《Journal of Electronics(China)》 2008年第2期274-276,共3页
In this letter,by employing Gaussian distribution to approximate the probability density function(pdf) of the extrinsic information at the output of the multiuser detector as a function of the pdf of the input extrins... In this letter,by employing Gaussian distribution to approximate the probability density function(pdf) of the extrinsic information at the output of the multiuser detector as a function of the pdf of the input extrinsic messages,it is concluded that the Probabilistic Data Association(PDA) algorithm is equivalent to the Soft Interference Cancellation plus Minimum Mean Square Error algo-rithm(SIC-MMSE) . 展开更多
关键词 Probabilistic Data Association (PDA) algorithm Soft Interference Cancellation plus Minimum Mean Square error (SIC-MMSE) algorithm probability density function (pdf)
下载PDF
RESEARCH ON THE MINIMUM ZONE CYLINDRICITY EVALUATION BASED ON GENETIC ALGORITHMS 被引量:9
18
作者 Cui ChangcaiChe RenshengYe DongHuang QingchengDepartment of Automatic Measurement and Control,Harbin Institute of Technology, Harbin 150001, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第2期167-170,共4页
A genetic algorithm (GA)-based method is proposed to solve the nonlinearoptimization problem of minimum zone cylindricity evaluation. First, the background of the problemis introduced. Then the mathematical model and ... A genetic algorithm (GA)-based method is proposed to solve the nonlinearoptimization problem of minimum zone cylindricity evaluation. First, the background of the problemis introduced. Then the mathematical model and the fitness function are derived from themathematical definition of dimensioning and tolerancing principles. Thirdly with the least squaressolution as the initial values, the whole implementation process of the algorithm is realized inwhich some key techniques, for example, variables representing, population initializing and suchbasic operations as selection, crossover and mutation, are discussed in detail. Finally, examplesare quoted to verify the proposed algorithm. The computation results indicate that the GA-basedoptimization method performs well on cylindricity evaluation. The outstanding advantages concludehigh accuracy, high efficiency and capabilities of solving complicated nonlinear and large spaceproblems. 展开更多
关键词 genetic algorithm (GA) CYLINDRICITY form error minimum zone
下载PDF
Measurement Uncertainty Evaluation of Conicity Error Inspected on CMM 被引量:11
19
作者 WANG Dongxia SONG Aiguo +2 位作者 WEN Xiulan XU Youxiong QIAO Guifang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第1期212-218,共7页
The cone is widely used in mechanical design for rotation, centering and fixing. Whether the conicity error can be measured and evaluated accurately will directly influence its assembly accuracy and working performanc... The cone is widely used in mechanical design for rotation, centering and fixing. Whether the conicity error can be measured and evaluated accurately will directly influence its assembly accuracy and working performance. According to the new generation geometrical product specification(GPS), the error and its measurement uncertainty should be evaluated together. The mathematical model of the minimum zone conicity error is established and an improved immune evolutionary algorithm(IlEA) is proposed to search for the conicity error. In the IIEA, initial antibodies are firstly generated by using quasi-random sequences and two kinds of affinities are calculated. Then, each antibody clone is generated and they are self-adaptively mutated so as to maintain diversity. Similar antibody is suppressed and new random antibody is generated. Because the mathematical model of conicity error is strongly nonlinear and the input quantities are not independent, it is difficult to use Guide to the expression of uncertainty in the measurement(GUM) method to evaluate measurement uncertainty. Adaptive Monte Carlo method(AMCM) is proposed to estimate measurement uncertainty in which the number of Monte Carlo trials is selected adaptively and the quality of the numerical results is directly controlled. The cone parts was machined on lathe CK6140 and measured on Miracle NC 454 Coordinate Measuring Machine(CMM). The experiment results confirm that the proposed method not only can search for the approximate solution of the minimum zone conicity error(MZCE) rapidly and precisely, but also can evaluate measurement uncertainty and give control variables with an expected numerical tolerance. The conicity errors computed by the proposed method are 20%-40% less than those computed by NC454 CMM software and the evaluation accuracy improves significantly. 展开更多
关键词 minimum zone conicity error improved immune evolutionary algorithm measurement uncertainty adaptive Monte Carlo method
下载PDF
CNC Thermal Compensation Based on Mind Evolutionary Algorithm Optimized BP Neural Network 被引量:6
20
作者 Yuefang Zhao Xiaohong Ren +2 位作者 Yang Hu Jin Wang Xuemei Bao 《World Journal of Engineering and Technology》 2016年第1期38-44,共7页
Thermal deformation error is one of the most important factors affecting the CNCs’ accuracy, so research is conducted on the temperature errors affecting CNCs’ machining accuracy;on the basis of analyzing the unpred... Thermal deformation error is one of the most important factors affecting the CNCs’ accuracy, so research is conducted on the temperature errors affecting CNCs’ machining accuracy;on the basis of analyzing the unpredictability and pre-maturing of the results of the genetic algorithm, as well as the slow speed of the training speed of the particle algorithm, a kind of Mind Evolutionary Algorithm optimized BP neural network featuring extremely strong global search capacity was proposed;type KVC850MA/2 five-axis CNC of Changzheng Lathe Factory was used as the research subject, and the Mind Evolutionary Algorithm optimized BP neural network algorithm was used for the establishment of the compensation model between temperature changes and the CNCs’ thermal deformation errors, as well as the realization method on hardware. The simulation results indicated that this method featured extremely high practical value. 展开更多
关键词 Thermal errors Thermal error Compensation Genetic algorithm Mind Evolutionary algorithm BP Neural Network
下载PDF
上一页 1 2 194 下一页 到第
使用帮助 返回顶部