基于DCT域的MPEG—2视频色度格式转换

提出了一种新的基于DCT域的MPEG-2码流转换算法，该算法与现有算法，即通过解码、空域采样率转换来设定新的码流参数，再编码的算法相比，无需IDCT、DCT操作，便可在DCT域实现码流转换，而且省去了运动矢量估值和运动补偿过程，不仅节省了大量帧存和减少了运算量，而且更具有实时性的优点，对MPEG-2 MP@ML到4：2：2Profile@ML码流转换算法实例的分析和现实表明：该算法能简单有效的实现压缩域码流转换，其思想同样可广泛用于其他基于DCT压缩图象的采样率转换、线性滤波等任务。     

一种支持密文转码的JPEG2000图像加密算法

针对异构化程度不断加剧的通信网络环境对码率转换能力的需求,提出了一种支持密文域转码的层次化加密算法CT-HEA。与以往基于JPEG2000图像的加密算法相比,CT-HEA针对率失真优化截断模型的特点,按照图像质量层和分辨率对压缩流重新进行截断与合并,对重组后的码流采用密码学算法进行分层加密。该算法支持对加密压缩流的透明码率转换。仿真实验结果表明,CT-HEA算法复杂度低、保密性好,具有灵活的安全转码特性和低的转码代价。     

抗MP3压缩的自适应音频盲水印算法

提出一种可抵抗MP3压缩的稳健的数字音频盲水印算法。该算法通过对音频小波域的近似分量进行分段以嵌入水印。水印提取时按音频特征实现自适应重分段,同时自动调整提取强度,解决了音频特征在MP3压缩前后不一致的矛盾,并实现了盲提取。实验结果显示该算法能有效抵抗MP3压缩、重采样、低通滤波和叠加白噪声等多种攻击。     

基于空间相关性的H.264误码检测算法

针对3G无线网络传输过程中引入的符合码流语义的内容误码,提出一种基于压缩域与像素域空间相关性的H.264误码检测算法。该算法利用压缩域DC系数空间相关性和像素域重建像素空间相关性来检测宏块是否存在误码。实验结果表明,在不同误码率和不同序列的情况下,采用该算法的解码器可有效检测误码,提高重建图像的质量。     

基于熵模型的压缩域运动对象检测

随着视频编解码技术的发展,H.264已成为最主要的标准之一。为了能从H.264码流中准确有效地分割和提取出运动对象,提出了一种压缩域下的对象检测算法。该算法主要利用压缩域下对象的运动矢量信息,先对矢量进行中值滤波预处理,目的是为了减少运动估计算法和对象实际运动所产生的误差。然后利用基于熵的原理,建立运动对象在空间和时间上的一致性模型。在该模型基础上,采用最大熵方法自适应获得阈值,检测得到运动对象。实验结果证明,该算法可以获得比较好的检测结果。     

视频转换编码中的压缩域运动补偿技术

研究视频转换编码中的压缩域运动补偿技术，对已有算法加以补充和完善，解决了现有算法不能处理运动矢量为负的问题。从具体实现角度，给出了详细的算法和必要的分析。实验结果表明基于该文所述的算法和分析改造的MPEG-2 TM5解码程序可以正确地实现压缩域运动补偿和空间分辨率下变换。     

基于压缩域水印的AVS视频认证*

为了提高压缩域视频水印的安全性,提出一种基于压缩域的AVS视频认证水印新算法。它从视频空间的三维特性出发,利用I帧分块能量关系、GOP结构信息、帧结构信息等构造特征码。在嵌入算法上,将特征码同时嵌入到中频DCT系数和运动矢量中,在认证端将重建特征值和提取的双水印进行比较。仿真实验结果表明,该算法具有较好的窜改认证能力。     

一种可抵抗MP3压缩的音频水印算法

提出了一种稳健的自适应混合域数字音频水印算法，该算法具有以下特点:(1)通过采纳更为稳健的同步信号及其全新嵌入策略，提高了音频水印的抗攻击能力；(2)充分利用DWT的多分辨率特性和DCT的能量压缩特性，改善了数字水印的隐藏效果；(3)结合听觉掩蔽特性自适应确定量化步长，提高了数字水印的不可感知性；(4)以保证不可感知性和稳健性的良好平衡为前提，实现了数字水印的盲检测．仿真实验表明，所提出的算法不仅具有较好的不可感知性，而且对诸如重新采样、重新量化、叠加噪声、低通滤波、随机剪切等攻击均具有较好的稳健性．特别地，该算法对于最为普通的MP3压缩攻击具有极强的抵抗能力(尤其是高压缩比下).     

图像差与加权核范数最小化的压缩图像融合

现有的图像融合算法存在非线性操作产生的噪声干扰和空间复杂度高等问题,使得融合图像易失真和丢失信息。一些学者提出的压缩感知图像融合算法能有效改善这一问题,但大多忽略了图像矩阵的低秩性,往往会降低融合质量。由此,将压缩感知融合技术与低秩矩阵逼近方法相结合,提出基于信息论图像差与自适应加权核范数最小化的图像融合算法。该算法由3个阶段组成。首先,将2幅源图像通过小波稀疏基稀疏化,并利用结构随机矩阵压缩采样,得到测量输出矩阵。然后,将测量输出矩阵进行分块,再利用图像差融合算法得到融合后的测量输出矩阵块。最后,利用自适应加权核范数最小化优化得到的块权重,通过正交匹配追踪法重建融合图像。实验结果表明了该算法的有效性和普适性,并且在多种评价指标上优于其他融合算法。     

基于自适应重采样的雷达信号压缩算法

针对实际应用中雷达采集的信号数据量较大、难以实时传输和存储的问题,提出一种基于自适应重采样的雷达信号压缩算法。对雷达信号进行分段处理,根据每段信号频谱的特点自适应地确定一个重采样率,通过对信号的重采样实现对雷达信号的压缩,利用零插值和低通滤波实现对信号的重构。实验结果证明了该算法的有效性。     

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。     

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.     

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.     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

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.     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

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     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.