基于通信编码的视频监控无损控制优化设计

在远程视频监控中,由于通信网络条件复杂,导致视频损坏,影响视频监控的准确性,需要对视频监控进行无损控制优化。提出一种基于通信编码的视频监控无损控制优化设计方法。构建通信网络下的远程视频监控系统模型,经过纠错预测及变换编码,对最初的数据进行映射转化,来剔除时间及空间上数据多余部分,设计基于通信编码的视频传输纠错算法,实现视频传输的无损控制。仿真结果表明,采用该方法能准确实现对视频序列的量化编码,提高编码效率,有效提高了视频监控的实时性和保真性,视频信号传输时间缩短12.3%,保真度提高15.4%,应用前景较好。     

基于码流掩盖定位的3G视频传输纠错算法

3G视频图像在互联网传输过程中,因丢包和网络时延等因素导致视频图像出现差错。传统方法采用视频感知的多粒度哈希纠错算法,当视频被快速篡改时出现码流模糊分块效应,导致视频传输质量不好。提出一种基于码流掩盖定位的3G网络视频传输纠错算法,采用隐马尔科夫模型进行丢包率预测。随机选择多个步长,进行码流迭代掩盖,设计篡改检测算法,用相似度来表述视频内容的差异程度,求解视频整体相似度,通过视频数据的帧间预测和层间预测实现对视频传输的纠错控制。仿真结果表明,该算法能有效降低视频传输的丢包和延时,峰值信噪比提高,视频纠错性能较好。     

光照突变环境下视频图像传输无损编码算法

光照突变视频信号在传输过程中容易受到外界干扰,导致视频通信丢包和失真,需要对视频信号进行无损编码处理。传统的编码算法采用分数阶傅里叶变换算法,受到高阶特征的非线性约束,导致视频编码性能不好。提出一种基于经验矩估计的光照突变视频无损编码算法,构建视频信号传输网络结构模型,进行关键帧特征提取,通过计算视频传输信号的经验矩估计特征,进行域特征点分离,通过幅频变换得到光照突变发生时的像素差,实现视频编码算法的改进,仿真结果表明,采用该算法能有效提高视频传输的正确前景点率,视频编码的码本准确度较高,保真性好,实现无损传输,提高视频通信的性能。     

基于物联网的远程视频监控优化方法研究

设计远程视频监控系统的关键是在于对视频图像的实时传输和数据通信设计,远程视频监控系统中接收端所显示的视频图像通常受到吞吐量和传输时延等因素的影响,导致远程视频监控实时性和保真性不好。提出一种基于物联网的远程视频监控优化方法。设计基于物联网的远程视频数据采集系统模型,构建远程视频监控识别的量化编码算法,使用RLE行程编码和Huffman编码来完成压缩任务,采用三级放大器进行逐级放大,进行远程视频监控。仿真结果表明,采用该方法进行远程视频监控,能准确实现对远程监控视频序列量化编码,提高远程视频监控的视频保真度和峰值信噪比,同时能提高视频传输效率,实现了视频远程监控的实时无损传输。     

一种基于视频的无损信息隐藏方法

描述了一种基于MPEG-Ⅱ彩色视频中的无损信息隐藏方法，该方法在Alattar算法的基础上，使宿主矢量类型的判别由四个不等式，减小到两个不等式，降低了算法的时间复杂度。数据嵌入过程中采用简单数据链路SDL成帧。在局域网上进行了隐秘传输模拟实验，从嵌入信息的视频中正确提取出所嵌入汉字或二值指纹图像后，原宿主视频可无损恢复。该方法较适用于视频中的隐秘传输及产权保护等领域。     

H.264帧内预测算法改进

帧内预测是H.264视频编解码标准中重要的组成部分,它能够显著提高压缩比率,但是大大提高了计算复杂度,很难运用到实时传输中,因此,如何提高运算速率是改进算法的核心问题。提出了一种快速模式选择算法,在保证图像质量的情况下较大地提高了帧内编码速度。     

基于视频压缩编码的动态图像水印方案

提出了一种新的基于视频压缩编码的动态图像水印方案。在嵌入水印时,充分考虑动态图像压缩编码的特性,对帧内编码帧(I帧),将水印信息嵌入到DCT低频系数中;而对帧间编码帧(P,B帧),结合动态补偿/离散余弦变换(MC/DCT)混介编码,把水印信息嵌入到运动补偿后的残差图像的自流成分中。同时,在水印嵌入时,采用扩频技术与多维水印相结合的方法,并通过相关检测的方法判断水印的存在。由于水印的检测是对视频码流直接实施的,不需要对压缩数据进行完全解码,从而大大降低了计算量,提高了视频数据水印的适用性。     

基于丢包率的改进前向纠错算法研究

针对移动环境下传输信道不稳定,从而造成数据丢失、语音频质量下降等问题,提出了一种基于丢包率的改进前向纠错算法。通过在接收端采用改进型归一化最小均方误差（MLMS）预测器来预测下一个前向纠错块中的丢帧个数,根据丢帧个数计算下一次的丢包率。该丢包率反映了当前的网络状况,这样发送端就可以根据接收端反馈回来的丢包率和丢包个数采取最佳的前向纠错编码方案。仿真实验结果表明,与传统前向纠错算法相比,该算法具有明显优势。     

一种低失真衰减的智能网络视频监控识别系统

基于音视频处理的图像传输和通信算法设计是实现网络视频监控和智能识别的基础,传统的网络视频监控识别系统因视频图像的传输过程中的时延敏感编码,导致失真衰减,视频识别性能不好。提出并设计了一种基于MPEG-4的网络视频监控及智能识别系统,用MUX101程控开关控制MPEG-4中的AD8021芯片进行反馈电阻控制实现视频放大,选用程控放大器VCA810,由DSP控制其控制电压达到调整放大倍数的目的,实现准确地采集网络视频数据。将RGB分量转化成亮度分量和色差分量,在使用RLE行程编码和Huffman编码来完成压缩任务,进行视频通信传输中的智能识别和监控,采用串并联复合式宽带阻抗匹配网络控制方法,提高数据采集系统的灵敏度和稳定性,抑制失真衰减,提高视频监控中对敏感特征的识别能力。系统测试结果表明,采用该系统进行网络视频智能监控识别,对敏感特征的检测的性能较好,能有效抑制失真衰减,提高对网络视频的识别精度。     

基于HEVC的ISC算法的颜色量化预处理

文章在基于HEVC框架下提出了增加颜色量化预处理的无损一维串匹配方法（Intra String Copy）。在没有颜色量化预处理环节的无损一维匹配算法可能会由于存在视频采集误差或是上下文造成的细微误差而导致匹配失败,这对以无损匹配为核心的ISC造成了很大的影响。文章借鉴了图像处理中八叉树的颜色量化方法,对视频图像信息进行颜色量化预处理后再进行一维串匹配编码,对屏幕图像视频的编码适应性有了很大的提升。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese     

More than Skin Deep – Understand Skin Biology by Means of Dermatogenomics

<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages.