基于对称延拓的纯二维双正交偶对称小波变换

研究了对称延拓在纯二维双正交偶对称小波变换中的应用,由纯二维小波滤波器组和对称延拓的性质推导出了小波分解后4个子带的公式。这些公式归纳了多级分解时,任意起点和任意长度的原始数据进行分解后,4个子带的周期和对称关系。最后给出了纯二维5/3小波变换的一个实例来具体说明其应用方法。     

地震信号小波变换的去噪方法

运用模极大值法基本原理进行地震信号去噪研究,进而运用二次小波变换原理通过低层系数处理对常用小波去噪方法进行改进.通过合成不同的染噪地震信号,由一系列仿真实验对模拟地震信号进行不同尺度的小波分解与重构,从而实现最优小波分解尺度上的地震信号噪声去除.与常用的快速傅立叶转换方法比较,仿真结果表明,该小波变换方法能够有效去除地震勘探信号中的噪声,并且针对系数的二次小波变换可以明显改进去噪的效果.     

基于最优小波和序列二次规划的信号压缩算法

为了寻找待压缩信号的最优小波,提出了一种适用于一维和二维信号的寻找其最优正交小波的算法.首先根据小波变换的多分辨分析原理,把待压缩信号投影在其小波变换子空间v-1和w-1上;然后令其在w-1上的投影达到最小并据此推出最优小波滤波器的推导公式;最后,基于序列二次规划求出给定信号的最优小波.实验清楚地显示了用新算法求出的最优小波的正确性,并表明用此算法得出的最优小波进行信号压缩,在压缩比不变的情况下,效果优于D-8小波等其他常见小波.     

基于二维正交小波滤波器设计方法

为研究滤波器优化问题,针对传统的可分二维滤波器无法做到信号的独特频率响应特征,在正交二维不可分滤波器组的设计中幅频特性的非连续性问题,提出了一种基于凸优化理论的二通道二维不可分的正交小波滤波器组设计方法.首先利用多相位矩阵的范数来近似二维滤波器组重建条件以获得一个凸优化问题,然后利用内点法计算该凸优化问题全局最优解,把最优解作为第二步非线性优化过程的初始值,最后利用标准的非线性迭代算法计算原问题的最优解.在Matlab环境下进行了仿真实验,仿真结果表明,相对于传统的二维通滤波器,方法改进的最优滤波器保证原问题的最优解的同时具有更好的频率响应特征,解决了传统二维通滤波器存在的幅频特性非连续性问题,并供了一种可供选择的正交变换工具.     

基于小波包分解的含噪语音时频特性分析 及端点检测

针对Hilbert—Huang变换方法在语音处理过程中存在模态混叠问题,本文提出了基于小波包分解的语音时频分析方法。首先对含噪语音进行小波包分解,对各分量分别进行经验模态分解,并运用相关系数阈值准则对固有模态函数进行筛选;然后建立语音信号的Hilbert谱和瞬时能量谱;最后将基于小波包分解的Hilbert—Huang变换瞬时能量谱方法应用于含噪语音的端点检测。实验结果表明：与传统广义维数以及谱熵算法相比,本文方法具有更好的准确性、稳定性和自适应性,能够有效描述语音信号非线性非平稳的时频特性,为语音信号的分析研究提供了一个新的思路。     

二维心音图特征提取与识别方法的研究

针对心音的特征提取问题,将一维心音信号转换成二维心音图,采用图 像处理技术提取心音的图像特征。本文首先对一维心音信号进行小波降噪和幅值归一化,将 处理后的心音信号转换成具有统一性和可比性的二维心音图,并进行预处理;然后结合心音 生理意义和二维心音图的图像特征,对能表征二维心音图生理信息的图像特征进行分析研 究,重点研究二维心音图纵横坐标比和拐点序列码特征;最后,基于纵横坐标比、拐点序列 码、小波分解系数3 个特征,探讨利用欧氏距离和支持向量机（SVM）两种识别方法进行 二维心音图分类和身份识别的可行性。实验结果表明,3 种特征都可以实现二维心音图的分 类识别,其中拐点序列码识别率最高;这种基于图像处理的二维心音图分类和身份识别方法 具有明显的可行性和实用性,拥有广阔的应用前景。     

关于子带编码中的最优对称小波

线性相位的对称小波在信号或图像压缩中有广泛的应用.对称小波有几个自由度的 选择灵活性,可以依信号或图像类型选择最优小波.文中讨论子带编码中的最优对称小波问 题,其最优性能指标为编码增益Gsbc达极大.对于平稳随机信号,最优小波唯一依赖信号的谱 密度.最后给出了几种典型谱密度分布所对应的最优对称小波.     

一种L型阵列的相干分步降维DOA估计方法*

针对相干信号二维波达方向(Direction Of Arrival,DOA)估计运算复杂度高的问题,本文提出了一种基于前后向空间平滑的分步降维MUSIC算法。该算法首先通过前后向空间平滑技术去相干,然后通过一维空间谱搜索得到一维入射角,最后通过最小二乘法得到二维入射角,进而得到相干信号的DOA。仿真实验表明该方法可以实现对相干信号的二维DOA估计,且具有较好的DOA估计性能,同时降低了运算复杂度。     

基于最小二乘支持向量机的汽轮机故障诊断

提出一种小波包分析与最小二乘支持向量机相结合的汽轮机故障诊断模型．对故障信号功率谱进行小波分解，简化了故障特征向量的提取．用二次损失函数取代支持向量机中的不敏感损失函数，将不等式约束条件变为等式约束．从而将二次规划问题转变为线性方程组的求解．选用RBF函数作为核函数。并提出对核函数的参数进行动态选取。提高了诊断的准确率．仿真结果表明该模型具有较强的非线性处理和抗干扰能力．     

基于二维快速广义S变换的人脸识别研究

针对人脸识别研究中,离散小波变换分辨率低的缺点及S变换虽分辨率高、方向性多,但计算复杂度高且冗余信息量大的现状,提出了二维快速广义S变换,克服了这些缺点。首先通过编程分析了二维快速广义S域幅度谱及相位谱,并重构原始信号,证明了二维快速广义S变换具有多分辨率和多方向性。其次,将二维快速广义S域的方向性与支持向量机（SVM）结合,将S域低频方向作为SVM的输入特征,实现对ORL标准人脸库中的人脸的识别与分类。实验结果表明：与离散小波变换相比,二维快速广义S变换与SVM相结合应用于人脸识别中,具有更高的识别率。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。