基于上下文的自适应二进制算术熵编码

H.264在主要档次中采纳了基于上下文的自适应二进制算术编码(CAbAC)的熵编码方案。深入研究了CAbAC的二进制化、上下文建模和自适应二进制算术编码器,并利用测试模型进行测试,实验结果表明:在相同测试序列下,CAbAC和CAVlC相比的确能节省较大的比特率

基于灰色关联度的小波图像压缩

小波变换在数字图像的压缩中起着极其重要的作用。本文结合小波分析理论和灰色关联分析原理,提出了一种新的图像压缩方法(gId-MEAn法),并与MATlAb中已有的方法进行比较。实验结果表明,无论是从压缩比还是失真度等指标来衡量,gId-MEAn法压缩后的图像效果都明显得到了提高

基于平稳环境下小波去噪的研究

中文摘要: 小波变换可以很好解决时间分辨率同频率分辨率之间的矛盾, 具有很好的时频特性。在环境变化相对平稳和主要噪声源预知的情况下, 用仪器同时测量需测信号和已知信号。用本文提供的方法, 算出此环境下已知信号中的噪声方差。再用它去滤除另一路信号中的噪声。实验表明, 该方法可以进一步提高信噪比

Wavelet Analysis of ECG Signal

利用小波变换能处理多尺度多分辨的特点,将心电信号进行多尺度分解,把不同频带的信号显现在小波分解各个尺度上。特征尺度上准确定位QRS波及T波的起始点,从而获得人体心电信号(ECG)中的QT间值。人体心电信号具有非平稳性和干扰多的特点,利用小波分析对心电信号进行处理能够获得精确的QT间值,为临床诊断提供了更加准确的依据。This paper shows how to acquire exact value of QT interval of ECG using wavelet analysis.ECG signals of different frequencies were extracted by multi-scales decomposition.Since QRS wave and T wave can be identified accurately by characteristic scales,QT interval can be captured exactly.The proposed method is especially suitable for ECG signals because these signals are unbalanced and noisy.When applied to real data,the method provides more accurate diagnostic information

Visual Simulation of Irregular Ocean Waves

摘要: 讨论了二维不规则长峰波和三维不规则短峰波的模型建立和仿真, 在MATLAB 基础上得到了较为理想的海浪模拟结果, 并 利用Visual C++开发了一个界面, 用以控制风速变化来查看波形的变化, 最后利用OpenGL 完成了三维波浪的显示。大量仿真结果证明, 本文所提的方法是可行且有效的, 对实际海浪具有良好的模拟效果。Abstract: The mathematical models of 2- D irregular long crested waves and 3- D irregular short crested waves are establish,and obtain perfect real wave effect base on Matlab.Exploit a interface base on Visaul C++,so we can observe the change of the ocean waves by wind velocity. In the end, finish the vision of 3- D ocean waves.Large amount of simulation experiments indicated that the methods presented in this paper are feasible and effective,which can successfully simulate the real ocean wave.基金项目: 厦门大学985 工程资助项

Dual Control With Probing for the Minimum Variance Problems

本文针对未知参数的最小方差控制问题,提出了一种在谨慎控制器基础上加入探测信号的控制策略。利用系统方差在参数辨识好坏时的变化调节探测信号的大小,避免了单纯使用谨慎控制所产生“关断“现象。与其它次优对偶控制相比,引入探测信号的最小方差对偶控制不仅计算量小易于实现,而且能够根据需要设计控制系统的动态性能、参数跟踪能力。This paper presents a dual control strategy with a probing signal for the minimum variance control problems with unknown parameters.The probing signal can be adjusted according to the variance change of the system to avoid the ‘turn off’ phenomenon which occurred with only caution control.Comparing with other sub-optimal dual controls,the dual control which introduces a probing signal can improve the dynamic properties and the parameters’ tracking ability to meet the requirements of the control system

PID Control Based on a New Genetic Algorithm

在遗传算法中引入一个学习过程,实现进化过程中同代个体之间相互竞争与学习的结合,并将其应用于PID控制中参数的整定.仿真结果表明此算法具有较好的寻优能力,初步验证了其引入学习过程的意义.In order to overcome the drawbacks of“early maturing”of the classical GA and improve its global convergency,this paper proposes a new process of learning which achieves the combination of competition with and learning from each other in the same generation.The simulation result of PID optimization shows that this proposed algorithm can effectively overcome the mentioned drawbacks and yield much better result compared with the classical GA

基于神经网络的手写数字识别

本文提出了一种采用bP神经网络方法来对无限制手写体数字进行识别的方案。通过图像预处理和数字特征提取,基于神经网络的判别方法,并结合使用MATlAb工具箱中提供的人工神经网络函数设计了一种手写数字识别的新方法。实验表明,该方法可以获得较好的识别率

基于多尺度小波变换的心电信号消噪

心电信号的消噪一直是人们关注的焦点,至今为止已经有许多论著针对心电信号的处理提出了不同的算法。本文以多尺度小波变换为理论背景,根据信号与噪声在小波变换下的不同特性,提出了一种阈值法和模极大值法相结合的小波消噪新算法。临床试验表明,该算法对心电信号的消噪具有良好的效果

The Analysis And Design Of Ocean Wave A lgorithm

摘要: 近年来, 对三维水的模拟尤其是海浪模拟日益成为人们关注的焦点问题, 逼真地再现三维海浪常常是电影、游戏等行业中要解决的的重点问题之一。本文采用了正余弦波形叠加和 iWave 两种方法进行海浪的模拟, 为了达到更佳的效果, 均对以上两种方法 均进行了优化改进, 最后对两种算法进行比较分析。 Abstract: In recent years,the simulation of 3D water especially ocean wave has been given more and more attention, realistically reappear 3D wave usually is one of the key problems, such as movie and game.etc. This paper use two kinds of method:positive cosine wave fold and Wave to simulate the ocean wave.for better effect,we optimize two arithmetics which discussed above,finally,we offer a comparative analysis of these algorithms厦门大学国家 985 工程信息科学学院科研基金(0000- x07204