基于S3C2410的WMA开源解码程序优化

针对MPlayer中WMA解码程序在S3C2410平台上解码效率低的问题,根据S3C2410平台的特性提出并分析了浮点运算转定点运算、以空间换时间以及手工汇编3种优化方案.详细介绍了定点化原理,并提出了模块化的优化方式,对MPlayer中的WMA解码程序进行优化.实验的结果表明了优化后的WMA解码程序在S3C2410平台上的解码效率已得到显著提高,已经能够流畅播放单通道的WMA文件.     

基于ARM9的H.264视频实时解码器研究与实现

通过分析JM H.264 Baseline Profile软件解码器的框架结构,根据影响解码速度的瓶颈,详细阐述了针对ARM9嵌入式平台上H.264视频实时解码算法的一整套优化方案;优化后,JM解码性能大大提高;最后结合ARM9的Friendly ARM mini2440开发平台,绐出了嵌入式H.264视频实时解码器的系统实现;实验结果表明,该解码器基本满足在嵌入式Linux平台下对qcif格式视频实时解码的需求.     

BMP文件解码的研究与实现

为解决当前位图文件（BMP文件）解码器存在的支持种类较单一的问题,探讨了BMP格式的多样性,有针对性地提出了一些解码思路.通过分析WindowsGDI（GDI＋）函数对BMP文件支持程度以及不同版本的Windows操作系统下用Windows自带程序对不同格式BMP的解码效果,说明了目前WindowsAPI函数在BMP解码上的格式支持局限性.设计并用C＋＋实现了BMP解码程序,对其解码支持格式与解码速度进行了验证,该解码程序支持BMP类型较全、速度较快,为BMP的解码器的设计提供了有益参考.     

基于BREW平台的H.264解码器的实现

介绍了H.264解码器在BREW平台上的实现方法,重点讨论了代码移植、优化和ARM编译过程中遇到的各种问题和相应的处理方法.并根据无线网络误码率高、误码常常造成播放中断等问题,实现了一种H.264解码器端的误码处理机制,使得解码应用程序的稳定性大大提高.在LG C910手机(ARM 9处理器)上的测试结果表明,对于QCIF格式的视频,在同时实现视频解码、显示以及QCP格式(QUALCOMM PureVoice)音频解码、播放等功能的情况下,优化后的H.264解码器仍可以达到9帧/s左右的解码和播放速度,满足了移动终端上的实时处理需求.     

ARM7平台实时MPEG-4解码系统的实现与优化

本文分析了ARM处理器的结构特点,介绍了在Freescale公司ARM7平台i. 250处理芯片上实现MPEG-4实时解码的策略,针对解码器的优化特点和芯片的硬件结构,采用了算法级、C语言级、ARM级联合优化的优化方法,对于标准MPEG-4解码过程进行了优化.实验结果表明,在采用该芯片的手机平台中,对于sub-QCIF大小的图像系统达到了平均约15fps的解码速度,成功实现了ARM7平台下的实时MPEG-4解码.该项目正与公司合作,具有优化后实时MPEG-4解码系统的低成本手机有望实现商业化.     

基于ARM的MPEG-4视频解码器

详细阐述了针对ARM平台的MPEG-4视频解码算法的优化方法。实验数据表明,优化后的解码器性能得到了全面提升。还结合ARM7TDMI的Easy ARM2200开发平台,给出了嵌入式MPEG-4视频解码的实时实现。     

基于TMS320C6416的DRM音频解码实现及优化

给出了数字广播调幅系统DRM的AAC音频解码器在定点DSP芯片TMS320C6416上的实现方案,从多方面对AAC音频解码器的关键技术进行优化.实验结果表明,算法的运行速度提高了10倍,存储器占用情况有较大改善,为DRM广播信号解码系统执行音频解码之前的解调和信道解码程序节省了很大的周期资源和处理空间.     

基于ARM7的MPEG-4视频解码器的优化

分析了ARM7处理器的结构特点,针对解码器的优化特点和芯片的硬件结构,采用了算法级、语言级、ARM级联合优化的方法,对标准MPEG-4解码过程进行了优化。通过本文所总结的ARM7TDMI上视频解码的优化方法,可以使MPEG4视频解码节约大量的数据处理时间,能较好地满足低分辨率、低帧率场合实时解码的要求。     

基于ARM存储结构的MP3程序性能优化

针对ARM存储系统的结构和MP3解码程序的特性,提出在S3C24A0上通过TLB,Cache和Write Buffer的有效使用,实现MP3解码程序性能优化,并且通过量化的比较得到一个可靠的结论.同时分析数据一致性问题,针对各种引起数据不一致的情况提出相应的解决方案.     

一种基于Linux的MP3播放器设计

本文讨论了一种基于Linux的MP3播放器的设计.系统基于Linux操作系统,利用GNU开发工具进行软件开发,使用C99标准的C语言编写,利用开源的高质量MPEG音频解码器MAD对MP3文件进行解码生成PCM数据,用ALSA中的PCM接口处理PCM数据,最后将数字信号转化为模拟信号,实现MP3音频的播放.     

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.