基于DSP与TLV320AIC23B的音频处理系统

介绍了基于DSP的音频处理技术,提供采用音频编解码芯片TLV320AIC23和DSP理器实现的音频处理系统的典型解决方案.音频编解码芯片完成模拟音频信号与数字信号之间的相互转换,包括语音信号采集和语音信号发送两部分.DSP处理器则完成对经模数转换后的语音信号在数字域处理的过程.该方案可以充分发挥DSP所具有的灵活性好、处理速度快的特点.     

基于DSP的音频信号采集和处理设计

提出一种基于TM320VC5409 DSP的音频信号处理系统,讨论VC5416与音频芯片TLV320AIC23和Flash存储器SST39VF400A的硬件接口设计,并通过对音频信号的采集与滤波来说明软件的实现过程.结果表明,该系统能够满足各种双声道的实时音频编解码的需要,可广泛用于音频处理的相关领域.     

基于ADSP2181的实时语音采集与处理板的原理与组成

把ＰＣ机接口技术与ＤＳＰ芯片技术相结合,设计了一块实时语音采集与处理板。由于采用了具有３０ｎｓ指令周期的ＡＤＳＰ２１８１芯片及专用的Ａ／Ｄ,Ｄ／Ａ芯片,本板能够对多种语音算法如Ｇ７２８,Ｇ７２９,Ｇ７２３,ＭＰＥＧ音频等算法实现实时编解码处理。由于这块板对外具有灵活方便的数字接口,它也可用于其他高速数字信号采集与处理应用的场合。     

基于DSP的声效处理器硬件设计与时序研究

针对特定环境(车内空间)内的声场重建,给出了声效处理器的硬件设计方案。以TI公司的数字信号处理器TMS320VC5402为硬件中心,对声音信号进行算法处理;串行16位模数转换芯片AD1870实现对音频信号的采集;串行数模转换芯片AD1858完成对处理后的音频信号的输出。详细叙述了TMS320VC5402和AD1870、AD1858之间的连接和时序。实验表明,此系统可靠、稳定,为完成音频信号的实时编解码提供了硬件支持,使在非规范空间播放高品质立体声音效成为可能。     

基于G.729a语音编解码的IP电话设计与实现

根据G.729a、RTP的参考文档,设计了基于G.729a语音编解码标准、RTP实时传输协议的IP电话原型,进行多媒体语音处理、音频编解码、实时传输功能模块的开发,同时在局域网环境下对该系统进行了测试。     

基于DSP和ARM的音频处理系统设计

根据TI公司的立体声音频编解码芯片TLV320AIC23的接口特点,结合数字信号处理技术和嵌入式系统的应用,设计了该芯片与TI公司DSP(数字信号处理)芯片TMS320VC5402和Samsung公司ARM芯片S3C4510B的硬件接口电路,ARM通过I~2C接口实现对AIC23的控制编程,完成AIC23的初始化。DSP通过其多通道缓冲串口McBSP与AIC23实现数据交换,完成音频信号的分析与处理。该系统适于语音信号编解码处理、语音识别和语音控制等应用。     

利用LPC2300系列ARM芯片的I~2S实现WAV文件播放

I2S(Inter-IC Sound Bus,集成电路内置音频总线)是工业领域或嵌入式系统领域常用的音频总线之一,它只处理音频数据,而其它信号如编码、控制等单独传送.使用I2S总线bus和支持该接口的编解码芯片连接,从而构建一个嵌入式音频系统.     

基于ARM的音频频谱显示器的设计

详细介绍了一种基于ARM的音频频谱显示系统的实现,整个音频显示系统包括音频信号采集、音频信号处理以及音频信号转换后的显示等功能。在设计中综合了声音采集、ARM技术及FFT算法,构建了一个实时采集的频谱显示系统,可以应用于各种需要对声音进行采集和分析的场合。其中,硬件系统主要包括声音信号的采集与处理、最小系统、电源和显示模块;而软件系统则是将ADC转换的数据通过FFT算法后显示在LCM12864显示器上。测试结果表明,该系统具有较好的实时性和准确性。     

利用ADPCM进行网络环境下实时多点语音通信

目前网络语音通信应用逐步增多,但效果还不甚理想。该文阐述了应用音频处理API函数、ADPCM编码调制技术和UDP协议进行网络环境下实时多点语音通信的方法,并给出其实现过程。实现机制为发送端利用低层音频服务的回调机制对音频数据块进行动态循环处理,防止了由于系统在写满语音输入缓冲区后,新、旧缓冲区交换时有一定的间隙而产生的输入数据泄漏。在传输之前采用ADPCM编码,有效地利用了现有带宽,传输后经缓冲解码再进行播放,尽可能地恢复原始语音信号。由于采用ADPCM编解码技术,实现了在各种网络环境下进行实时多点语音通信,效果较为理想。     

基于DSP的声信号降噪系统的设计与实现

基于DSP TMS320VC5502和音频采样芯片TLV320AIC23构建了声信号降噪系统,分析了该系统的总体结构设计和软件处理流程设计.在DSP/BIOS控制机制下,建立了基于DMA、双缓冲区切换和中断响应机制等技术的音频信号采集与处理的程序框架.提出了一种基于多分辨分析的小波频带阈值降噪方法,并应用TDS5502EVM板和TDS560仿真器对优化的小波阈值降噪算法进行了实时仿真,实现了对强噪声语音信号的分析与降噪处理,并通过一个实例信号验证了系统的良好性能.     

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.