Conditions for stability of the extended Kalman filter and their application to the frequency tracking problem

The error dynamics of the extended Kalman filter (EKF), employed as an observer for a general nonlinear, stochastic discrete time system, are analyzed. Sufficient conditions for the boundedness of the errors of the EKF are determined. An expression for the bound on the errors is given in terms of the size of the nonlinearities of the system and the error covariance matrices used in the design of the EKF. The results are applied to the design of a stable EKF frequency tracker for a signal with time-varying frequency.This research was supported by the Co-operative Research Centre for Robust and Adaptive Systems ((CR)² ASys). The authors wish to acknowledge the funding of the activities of (CR)² ASys by the Australian Commonwealth Government under the Co-operative Research Centre Program.     

Probabilistic linear models for multiresolution estimation in gray-level images

A multiresolution analysis of digital gray-level images is presented. A gray-level multi-scale framework is determined from two main assumptions: the gray scale is binary at the finest spatial resolution, and the gray levels of composed regions are obtained additively. In order to interrelate the gray-level histograms of the same image at different resolutions, probabilistic linear models are developed, which are then applied for estimation. Linear-optimization theory is used as a way of constructing such models. A general procedure for image processing is sketched, based on gray-level estimation. A versatile algorithm for nonlinear filtering is derived. Some examples of prospective applications are given.This work was partially supported by grant TIC91-646 from the DGYCIT of the Spanish Government.     

方盒形带凸缘件的板料形状优化设计

本文用大变形刚塑性有限元模拟正方形板料在方冲头拉延下的凸缘变形过程，并以所获得的工件形状与金属流动方向为依据，对初始板料形状进行修正。对修正后的坯料形状进行二次模拟，获得了与给定凸缘形状基本吻合的拉延件形状。文中对不同凸缘圆角对极料优化形状的影响作了计算，讨论了在保证边界轮廓位置不变的条件下网格划分的方法。     

聚腈分子的飞秒时间分辨光克尔效应

本文利用飞秒时间分辩光克尔效应，对主链为Ｃ＝Ｎ结构的两种共轭聚腈高分子的溶液和薄膜进行研究，所测得的时间分辨光克尔信号均表现为超快响应。     

掺杂染料的向列相液晶微粒材料的非线性光学研究

对布满液晶微粒的聚合物(PDLC)进行了简并四波混频及光学双稳态的研究,并在文中对相关的PDLC中的分子重取向和热效应的非线性光学效应进行了讨论.     

Application of Galerkin Method to Dynamical Behavior of Viscoelastic Timoshenko Beam with Finite Deformation

The motion equations governing the dynamical behavior of a viscoelasticTimoshenko beam with finite deformation are derived and simplified byGalerkin method. The viscoelastic material is assumed to obey thethree-dimensional fractional derivative constitutive relation. Thedynamical behaviors of the simplified systems with order 1 and order 2are numerically computed and compared by using the computational methodpresented by the authors. The dynamical behaviors of the systems areuniform qualitatively, but there is a little deviation quantitatively.And the truncated system with order 1 is safer than the one of order 2.It is also shown that the lower order system is reasonable. Theinfluences of the load parameter and the fractional derivative parameter(material parameter) on the deflection of the beam are consideredrespectively. The numerical methods in nonlinear dynamics, such as phasediagram, and Poincaré section, are applied to reveal dynamical behaviorsof the nonlinear viscoelastic Timoshenko beam. There are plenty ofdynamical behaviors, such as periodicity, bifurcation, quasi-periodicityand chaos in the dynamical system.     

鱼雷罐喷粉预处理优化研究

在已经得到的描述鱼雷罐喷粉处理基本参数具体表达式的基础上，运用多目标非线性优化方法，对工艺操作参数进行优化。     

自发参量下转换光场的实验研究进展综述

自发参量下转换(spontaneous parametric down-conversion,SPDC)光场是基于单色泵浦光子流和量子真空噪声对非线性晶体的综合作用而产生的,它固有的量子起源决定了在非经典光场研究中的重要地位和作用.对SPDC光场的相干特性和它在绝对测量光电探测器量子效率中的应用进行了深入而细致的研究和探讨.     

On‐Line Detection Of State‐Of‐Charge In Lead Acid Battery Using Radial Basis Function Neural Network

To realize a stable supply of electric power in an automobile, an accurate and reliable detection method of SOC (state‐of‐charge) in a lead acid battery is required. However the dynamics of the battery is very complicated. The characteristics of the battery greatly change due to its degradation. Moreover a automobile has many driving patterns, which are unknown beforehand. Thus it is not easy to detect the SOC analytically. In this paper, to overcome this problem, a new on‐line SOC detection method with a radial basis function neural network is proposed. In order to increase the detection accuracy of degraded batteries, physical values related to the degradation degree are used as input signal in the neural network. The detection accuracies for different sized batteries and various degradation states are investigated.     

电站并联运行的不对称非线性振荡

本文给出一个结构不完全对称并联电网的等价定理,它把双输入双输出非线性耦合的微分方程组等价为单输入单输出的非线性微分方程,然后用渐近方法和谐波线性化方法求其一次近似解,得到一些新的物理性质,有助于合理选择电网结构,以提高其结构稳定性.