一种新的运动自适应去隔行算法

提出基于棱边方向检测的运动自适应去隔行算法,该算法能充分利用图像序列的时间和空间上的相关信息,采用新颖的相邻场运动检测方法区分视频序列中的运动和静止部分.对于运动部分,使用改进的基于棱边方向的边沿自适应插值算法;对于静止部分,采用三点中值滤波插值算法.仿真实验表明：算法无论在画面视觉效果还是视频图像信噪比,均达到良好了效果.     

特殊靶标图像的Otsu自适应双阈值分割法

针对特殊管道弯曲度测量光斑的高精度定位要求,提出了一种特殊靶标图像的Otsu自适应双阈值分割法。介绍了基于准直激光管道弯曲度测量原理,先对特殊靶标图像进行处理,然后对整个图像灰度分布统计特性进行计算,建立起计算自适应双阈值的数学模型,从而实现特殊靶标图像自适应双阈值分割。实验结果表明,该方法具有较强的稳定性、实时性好、靶标图像分割效果较好,提高了光斑的定位精度。     

ADAPTIVE CONTROL AND IDENTIFICATION OF CHAOTIC SYSTEMS

A novel adaptive control and identification on-line method is proposed for a class of chaotic system with uncertain parameters. We prove that, using the presented method, a controller and identifier is developed which can remove chaos in nonlinear systems and make the system asymptotically stabilizing to an arbitrarily desired smooth orbit. And at the same time, estimates to uncertain parameters converge to their true values. The advantage of our method over the existing result is that the controller and identifier is directly constructed by analytic formula without knowing unknown bounds about uncertain parameters in advance. A computer simulation example is given to validate the proposed approach.     

ADAPTIVE NONLINEAR FEEDBACK CONTROL OF CHAOTIC SYSTEMS BASED ON REDUCED PARAMETER QUADRATIC PREDICTORS

An adaptive nonlinear feedback-control method is proposed to control continuous-time chaotic dynamical systems, where the adaptive nonlinear controller acts on only one-dimensional error signal between the desired state and the observed chaotic state of a system. The reduced parameter adaptive quadratic predictor used in adaptive feedback cancellation of the nonlinear terms can control the system to any desired state. Computer simulation results on the Lorenz system are shown to demonstrate the effectiveness of this feedback-control method.     

Local and Parallel Finite Element Algorithms Based on Two-Grid Discretizations for Nonlinear Problems

In this paper, some local and parallel discretizations and adaptive finite element algorithms are proposed and analyzed for nonlinear elliptic boundary value problems in both two and three dimensions. The main technique is to use a standard finite element discretization on a coarse grid to approximate low frequencies and then to apply some linearized discretization on a fine grid to correct the resulted residual (which contains mostly high frequencies) by some local/parallel procedures. The theoretical tools for analyzing these methods are some local a priori and a posteriori error estimates for finite element solutions on general shape-regular grids that are also obtained in this paper.     

Gradient recovery type a posteriori error estimate for finite element approximation on non-uniform meshes

In this paper, we derive gradient recovery type a posteriori error estimate for the finite element approximation of elliptic equations. We show that a posteriori error estimate provide both upper and lower bounds for the discretization error on the non-uniform meshes. Moreover, it is proved that a posteriori error estimate is also asymptotically exact on the uniform meshes if the solution is smooth enough. The numerical results demonstrating the theoretical results are also presented in this paper.     

基于重叠正交变换的自适应图像水印

本文提出了一种基于重叠正交变换（LOT）的自适应图像水印算法,给出了水印嵌簇检测的详细算法设计,数字图像水印是最近发展起来的一项新技术,它为图像的版权保护问题提供了一种新的解决思路,本文首次在水印算法中采用了LOT以代替传统的离散余弦变换（DCT),从而有效地避免了DCT的块效应,同时,本文还利用人的视觉系统（HVS）特性,在对图像块进行分类的基础上完成水印的自适应嵌入,实验结果表明,本文所提出的图像水印算法有效地提高了水印的鲁棒性和透明性。     

双基地机载预警雷达空时自适应处理方法

本文在文献[1] 所建杂波模型的基础上,进一步研究空时自适应处理对双基地机载预警雷达杂波的抑制问题.深入分析了双基地机载预警雷达杂波距离多普勒特性,进而提出了一种基于距离多普勒补偿的空时二维自适应处理方法.理论分析与计算机仿真表明,该算法能有效实现工作于低重频时双基地机载预警雷达杂波抑制.     

相控阵雷达中的自适应搜索研究

本文研究了相控阵雷达中的自适应分区搜索算法及性能.首先,推导了最优分区搜索性能及其与均匀搜索性能的关系,分析了目标强度估计误差对最优分区搜索性能的影响;然后,分别研究了平稳目标分布和非平稳目标分布环境下的自适应搜索方法、最优参数和性能.     

High-Speed Downlink Access in 3G Systems: A Portent for the Evolution of 4G Systems?

Due to the need of operators to protect the high levels of investment inthird generation (3G) wireless systems, it seems likely that the path tofourth generation (4G) wireless systems will be evolutionary rather thanrevolutionary. Currently there are a number of proposals beforestandardisation bodies such as 3GPP and 3GPP2 for extending the relevant3G systems to handle asymmetrical, packet-orientatedservices with very high downlink capacities. These proposals, whichinclude HDR and 1XTREME, may pave the way towards 4G systems.This paper outlines some of the salient features of HDR and 1XTREME:adaptive modulation, advanced hybrid ARQ, new fast access controlschemes, etc. On the basis of the trends inherent in theseproposals, some possible directions for the development of 4G systems arediscussed.