基于语音质量预测的Speex自适应码率控制算法

为实现IP语音(VoIP)质量的动态管理与控制,提出了一种基于语音质量预测的自适应码率控制算法。通过实时预测VoIP通话的瞬时语音质量和总体语音质量,自适应地调整Speex编码参数,从而根据需要选择最佳编码速率。实验仿真结果表明,提出的算法能够有效减少网络拥塞,提高VoIP系统的语音质量。     

IEEES02．11b无线局域网的VoIP通信容量计算及分析

针对用IEEE802．11b网络建立低成本的无线VoIP网络进行分析研究，本文评估在不同的时延限制、信道质量参数和语音音质指标下运载语音通话的能力，并比较G．711和G．729两种语音编码方案下不同的语音数据分组长度时的效果，为在无线环境下以IP方式构造移动语音通信网络奠定了良好的基础。     

基于网络性能的VoIP语音质量评价模型

在VoIP应用中,为了实现服务质量的监测和路径切换,通常需要测量路径的网络性能,并将网络性能映射到语音质量评价.本文提出一种基于网络性能的VoIP语音质量评价模型,该模型在E-Model的基础上进行了改进,只考虑网络性能的动态变化对语音质量的影响.新的模型考虑更少的影响因素,比E-Model更容易计算,因此更适用于VoIP系统的语音质量评价.通过实验比较了新的模型和简单的网络参数评价模型,结果显示该模型具有更好的语音质量描述能力.     

基于特征比较的语音评分方法研究

为在语言朗读训练时对跟读语音的质量自动作出客观评价并在嵌入式系统上实现,提出了一种基于特征比较的语音评分方法。通过分析输入语音,提取语音特征并与参考标准进行匹配比较,由评分机制根据相似程度大小给出评价得分。实验证明该方法的算法复杂度较低,评分结果符合人的主观感觉。     

IEEE 802.11b无线局域网的VoIP通信容量计算及分析

针对用IEEE 802.11b网络建立低成本的无线VoIP网络进行分析研究,本文评估在不同的时延限制、信道质量参数和语音音质指标下运载语音通话的能力,并比较G.711和G.729两种语音编码方案下不同的语音数据分组长度时的效果,为在无线环境下以IP方式构造移动语音通信网络奠定了良好的基础.     

基于数字助听器声音场景分类的噪声抑制算法

提出了一种基于声音场景分类的噪声抑制算法。算法使用调制滤波法对纯语音、纯噪音和含噪语音3种场景进行分类,并根据分类结果调整噪声抑制算法参数集,得到不同的抑制系数。本文方法在助听器测试系统中取得了良好的实验效果,场景分类正确率在95%以上。在不同噪声类型情况下,经过本文算法处理的输出语音信号取得了良好的信噪比和MOS评分的提升。本文算法可以有效地提高数字助听器输出语音质量。     

特征联合优化深度信念网络的语音增强算法

针对深度信念网络（Deep Believe Network，DBN）模型泛化能力较弱，导致语音增强效果不佳的问题，提出了一种特征联合优化的回归DBN语音增强算法。该算法对语音和噪声不做任何假设。该算法分别提取语音信号的LMPS（Log-Mel frequency Power Spectrum）和MFCC（Mel-Frequency Cepstral Coefficients）特征。LMPS用于直接重构增强语音，保证了语音听觉质量，MFCC作为辅助次级特征。将两种特征联合输入到DBN体系中对网络参数进行优化。这种联合优化在对LMPS的直接预测中加入MFCC限制，提升了模型对LMPS估计的泛化能力，更加准确地重构增强语音。仿真结果表明，在不同的信噪比环境下，与LPS（Log Power Spectrum）和LMPS单特征优化相比，LMPS和MFCC联合优化使增强语音获得了较高的PESQ和SNR，提高了语音质量和可懂度。     

基于TD—PSOLA普通话韵律参数修改的实现

在普通话文语转换系统中,如何精确控制韵律参数修改是关系到合成语音质量的关键.根据汉语普通话的韵律特征,采用TD-PSOLA算法,精确实现了的韵律参数的修改.用分时段直线韵律参数模型,动态生成基音轮廓,计算出合成基音标记,一次性实现基频尺度修改和时间尺度的修改.根据自然语音与模拟合成出来的语音韵律参数比较分析表明,能有效地控制韵律参数,达到预期的参数合成目标,并且具有较高质量.也可以进行进行参数合成运算量少,控制参数精确,合成语音清晰自然.     

一种基于改进谱减法的语音去噪新方法

介绍了改进谱减法的原理及算法。提出在信噪比（SNR）较低的情况下，根据语音短时能量和过零率，判断在无声或有声期间是否偶然的噪声过高，从而设定合适的参数降低噪声。实验证明该方法提高了输出信噪比，改善了语音质量，具有良好的语音去噪的效果。     

基于无线传感器网络的语音通信系统设计与实现

针对无线传感器网络在语音方面的应用进行深入研究,提出一种基于无线传感器网络的语音通信系统。根据无线传感器网络工作原理和节点体系架构,设计了以嵌入式处理器MPC2194为核心,结合无线收发器CC1000、语音采集编码芯片CMX649以及存储芯片、电源等外围电路构建的语音无线传感器节点。重点讨论了系统结构、硬软件设计和协议栈开发等关键问题。并通过实验选择优化系统参数,从而实现高质量语音通信。     

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.