基于HMM/SVM两级结构的汉语易混淆语音识别

基于HMM的汉语语音识别中,易混淆语音的识别率仍然不高.在分析HMM固有缺陷的基础上,本文提出一种使用SVM在HMM系统上进行二次识别来提高易混淆语音识别率的方法.通过引入置信度估计环节,提高系统性能和效率.通过充分利用Viterbi解码获得的信息来构造新的分类特征,从而解决标准SVM难以处理可变长数据的问题.详细探讨这种两级识别结构中置信度估计、分类特征提取和SVM识别器构造等问题.语音识别实验的结果显示,与采用HMM/SVM混合结构的模型相比,本文方法在对识别速度影响很小的情况下可以使识别率有明显提高.这表明所提出的具有置信估计环节的HMM/SVM两级结构用于易混淆语音识别是可行的.     

基于隐马尔可夫模型的人脸检测与识别

此文讨论了隐马尔可夫模型(HMM)在人脸检测与识别中的实现及其逐步改进.采用了基于DCT系数的伪二维隐马尔可夫人脸模型(P2D-HMM).由于此模型更好的利用了人脸图象的二维统计特性,所以与基于KLT系数的一维隐马尔可夫人脸模型相比,识别效果更好.虽然一维隐马尔可夫模型(1D-HMM)表现二维人脸存在不足,但训练识别比较简单.P2D-HMM可以充分表现二维人脸模型的统计特性,但结构复杂、运算量大.综合考虑二者的优缺点,结合支持向量机(SVM)对静态数据识别效率明显的长处,建立了SVM和HMM的混合人脸识别模型.采用独立分量分析(ICA)的方法提取人脸区域的特征,作为SVM的输入.在ORL人脸库中,测试基于1D-HMM、P2D-HMM和SVM/HMM的人脸识别方法,识别率分别达到86.2%、97.2%和97.0%,并且以上方法对姿态和环境的变化具有较好鲁棒性.     

基于多尺度特征的双层隐马尔可夫模型及其在行为识别中的应用

借鉴人类视觉感知所具有的多尺度、多分辨性的特性,针对智能视频监控系统的人体运动行为识别,提出了一种基于多尺度特征的双层隐马尔可夫模型.根据人体行为关键姿态数确定HMM的状态数目,发掘人体运动行为隐藏的多尺度结构间的关系,将运动轨迹和人体姿态边缘小波矩2个不同尺度特征应用于2层HMM,提供更为丰富的行为尺度间的相关信息.分别用Weizmann人体行为数据库和自行拍摄的室内视频,对人体运动行为识别进行仿真实验,结果表明,五状态HMM模型更符合人体运动行为特点,基于多尺度特征的五状态双层隐马尔可夫模型具有较高的识别率.     

基于傅里叶-隐马尔科夫模型的人体行为识别

研究人行为识别的正确性,针对提高对人体行为序列图像进行识别的能力,隐马尔科夫模型(HMM)是一种统计分析模型,具有时序模式分析能力.为了增加图像信息的有效性,提出了一种傅里叶与隐马尔科夫模型相结合的方法人体行为识别方法.通过获得各种人体行为的二值图像序列,对待识别的序列图像提取具有旋转、平移和尺度不变性的傅立叶特征,采用了一种基于中心距的傅里叶描述子,利用改进的隐马尔科夫模型对提取的特征向量进行分类,得到人体行为的识别结果.试验结果表明,系统的识别率与HMM的状态数和观察值数有关,方法是有效且可行的,设计适当的HMM分类器能使系统的识别率达到90%以上,实际应用效果满足要求.     

基于隐马尔可夫模型的自动人脸识别方法

基于DCT系数的伪二维隐马尔可夫人脸模型(P2D HMM)由于更好的利用了人脸图像 的二维统计特性,所以与基于KLT系数的一维隐马尔可夫人脸模型相比,识别效果更好,但是结构复 杂、运算量大。一维隐马尔可夫模型(1D HMM)表现二维人脸存在不足,但训练识别比较简单。综合 考虑二者的优缺点,结合支持向量机(SVM)对静态数据识别效率明显的长处,建立了SVM和HMM 的混合人脸识别模型。采用独立分量分析(ICA)的方法提取人脸区域的特征,作为SVM的输入。在 ORL人脸库中,测试基于SVM/HMM的人脸识别方法,实验结果表明该方法在获得与P2D HMM相应 的识别率的前提下,结构简单,运算量小。     

一种基于消除能量偏差的双层环境声识别模型

相比Mel倒谱系数(MFCC),基于能量偏差移除和幂函数的声音特征(PNCC)具有较强的抗噪能力.首先,将PNCC和MFCC组成混合特征矩阵,在隐马尔科夫模型(HMM)、高斯混合模型(GMM)和支持向量机(SVM)下对混合特征和传统特征做对比实验.其次,先选取实验结果较好的HMM模型过滤测试样本,再分别选取GMM和SVM做二次分类,并测试两种双层模型的识别正确率.结果表明在噪声环境下使用HMM/GMM双层模型和混合特征可取得较好的识别效果.     

一种简便的视角无关动作识别方法

针对日常生活中人体执行动作时存在视角变化而导致难以识别的问题,提出一种基于视角空间切分的多视角空间隐马尔可夫模型（ HMM）概率融合的视角无关动作识别算法。该方法首先按照人体相对于摄像机的旋转方向将视角空间分割为多个子空间,然后选取兴趣点视频段词袋特征与分区域的光流特征相融合,形成具有一定视角鲁棒性特征对人体运动信息进行描述,并在每个子视角空间下利用HMM建立各人体动作的模型,最终通过将多视角空间相应的动作模型似然概率加权融合,实现对未知视角动作的识别。利用多视角IXMAS动作识别数据库对该算法进行测试的实验结果表明,该算法实现简单且对未知视角下的动作具有较好识别结果。     

基于“快速投票”算法的HMM／SVM混合识别模型及应用

提出一种基于隐马尔可夫模型（HMM）和支持向量机（SVM）的双层过滤识别系统。根据隐马尔可夫模型训练中不同结构的序列其L值分布范围不同的特点，对传统多类“投票模型”进行改进，提出一种“快速投票”算法。先用HMM对人类内含子和外显子进行识别，同时，对于L值区域有重叠造成识别率较低的部分，再用支持向量机进行第二次识别过滤。这一模型克服了传统用单一HMM识别方法的不足，实现了HMM和SVM的优势互补。实验表明，用HMM／SVM进行两类识别，其平均识别率达到了90％，进行多类识别，平均识别率达到了91．5％。     

基于手势识别的机器人人机交互技术研究

研究了基于视觉的动态手势识别技术,采用基于肤色的高斯模型与改进的光流场跟踪算法结合的方 法,实现了复杂背景下实时的手势跟踪,具有快速和准确的特点,且具有较好的鲁棒性．对于动态手势识别器,采 用了隐马尔可夫模型（HMM）作为训练识别算法．考虑到动态手势特征本身的一些特点,对HMM 参数优化算法重 估式加以修正,调整了算法比例因子,从而推导了最佳状态链的确定算法、HMM 参数优化算法．最后将研究开发 的动态手势识别算法成功地应用到了基于网络的远程机器人控制系统中．     

基于HMM和SVM串联模型的低空飞行目标声识别方法

为弥补单一模型在识别低空飞行目标时的不足,进一步提高识别概率,提出了一种基于HMM(HiddenMarkov model)和SVMs(Support vector machines)串联结构的低空飞行目标声识别方法.针对战场环境下声信号的特点,该方法综合考虑HMM适合处理连续动态信号及SVM小样本情况下的强分类能力,先由HMM计算各HMM模型与待辨识信号的匹配程度,形成匹配度特征向量,再利用SVM适合分类的优势,对匹配度特征向量做进一步决策,得到最后的识别结果,弥补了单一模型在识别低空飞行目标时的不足.实际数据的识别分析结果表明了该方法在低空飞行目标声识别中的准确性与有效性.     

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     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.