非线性模糊直接鲁棒自适应控制的后推设计

采用模糊直接控制方法,针对一类非线性多入多出系统,提出了一种带有连续鲁棒项的鲁棒自适应控制方法.在此基础给出了高阶多入多出系统的鲁棒自适应的后推设计方法.在鲁棒项合理简化的情况下,给出了系统Lyapunov意义下的稳定性证明,简略分析了各设计参数的物理意义及其对系统性能的影响.理论分析和仿真实验均显示,本方法可以使系统全局渐近稳定,且选取恰当的设计参数可保证系统对输入信号的跟踪达到任意精度;并且由于鲁棒项的引入可使系统的设计更具灵活性.     

A new algorithm for fixed design regression and denoising

In this paper, we present a new algorithm to estimate a regression function in a fixed design regression model, by piecewise (standard and trigonometric) polynomials computed with an automatic choice of the knots of the subdivision and of the degrees of the polynomials on each sub-interval. First we give the theoretical background underlying the method: the theoretical performances of our penalized least-squares estimator are based on non-asymptotic evaluations of a mean-square type risk. Then we explain how the algorithm is built and possibly accelerated (to face the case when the number of observations is great), how the penalty term is chosen and why it contains some constants requiring an empirical calibration. Lastly, a comparison with some well-known or recent wavelet methods is made: this brings out that our algorithm behaves in a very competitive way in term of denoising and of compression.     

Modification of Spatial Coherence by Means of Low-Order Zernike-Mode Adaptive Optics

Spatial coherence of the field modified by low-order adaptive optics is analyzed to establish a theoretical basis for the recent idea of using adaptive optics as a spatial coherence modifier. In this context low-order adaptive optics has the ability to correct some of the low-order aberrations specified by Zernike polynomials. The initial field to be modified is assumed to be a spatially partially coherent one resulting from phase disturbance. It is demonstrated, as in the previous study, that low-order adaptive optics serves to enhance the spatial coherence of the resultant field and that the effect of the enhancement becomes stronger as the spatial coherence of the initially partially coherent field increases. Potential applications of low-order adaptive optics as a spatial coherence modifier are briefly discussed.     

基于指数分布的进化策略

典型的进化策略受自然进化过程的启发而成为求解全局优化问题的重要方法。传统的ES变异算子作为一个主要的进化技术是建立在正态分布的随机变量基础上的，本文提出了基于指数分布的进化策略由于采用了新的变异算子有效地减少了产生探试解的成本，从而优于传统的进化策略。     

On the Solution of Discontinuous IVPs by Adaptive Runge–Kutta Codes

In this paper an automatic technique for handling discontinuous IVPs when they are solved by means of adaptive Runge–Kutta codes is proposed. This technique detects, accurately locates and passes the discontinuities in the solution of IVPs by using the information generated by the code along the numerical integration together with a continuous interpolant of the discrete solution. A remarkable feature is that it does not require additional information on the location of the discontinuities. Some numerical experiments are presented to illustrate the reliability and efficiency of the proposed algorithms.     

一种直线逼近渐开线齿廓曲线的自适应算法

从渐开线弧长公式出发，引入一种能根据加工精度要求来确定逼近线段的段数，并使节点在渐开线齿廓曲线上分布均匀的自适应计算方法。给出计算实例及用AutoCAD来绘制齿轮的方法．以及用VLisp语言编制计算程序和绘图程序的框图。     

神经网络自适应控制器设计

对前馈神经网络用于动态系统的辨识、自适应控制进行了分析和数学推导，给出了自适应神经网络控制器的设计方法．最后通过仿真实例进行了说明．     

耦合发电机系统的自适应控制与同步

讨论了耦合发电机系统的自适应控制和参数未知时的自适应同步问题.设计了自适应控制器，将耦合发电机系统的混沌轨道镇定到平衡点，并使得两个参数未知的耦合发电机系统达到了混沌同步.数值模拟验证了所设计的控制器的有效性. 关键词： 耦合发电机系统 自适应控制 平衡点 同步     

基于像素特征的路面裂缝图像自适应滤噪

分析了破损路面图像的像素点区域特征，针对不同区域提出加权邻域滤波和自适加权中值滤波算法。其权值是通过对图像中区域特征的推理得到的，所以算法中能根据图像的区域特征自适应的进行滤波。试验表明，本算法能够有效滤除噪声，并具有很好的细节保护能力。     

Least‐squares finite element method on adaptive grid for PDEs with shocks

We apply the least‐squares finite element method with adaptive grid to nonlinear time‐dependent PDEs with shocks. The least‐squares finite element method is also used in applying the deformation method to generate the adaptive moving grids. The effectiveness of this method is demonstrated by solving a Burgers' equation with shocks. Computational results on uniform grids and adaptive grids are compared for the purpose of evaluation. The results show that the adaptive grids can capture the shock more sharply with significantly less computational time. For moving shock, the adaptive grid moves correctly with the shock. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006