用于AVS—M标准的差错复原编码方案

基于无线移动网络的视频通信业务越来越受到重视。无线网络属于易于发生差错的信道，基于无线移动网络的视频通信业务必然要受到信道差错的影响。为了对抗信道差错，必须采取适当的技术措施。目前，差错复原技术已成为易发生差错信道下视频编码的重要组成部分。AVS—M标准是我国自主制定的视频压缩编码标准，对AVS—M标准的差错复原技术进行研究具有重要的意义。提出了两套用于AVS-M标准的差错复原编码方案，并对其差错复原性能进行了实验研究。实验结果表明，这两套方案具有良好的差错复原性能，重建图像的主客观质量均得到了明显的改善。     

Na(THF)2(μ2-η5-Cp)(η5,η5,η1-Cp3Yb)(THF)]n: The synthesis and X-ray structure of an anionic organolanthanidepolymer formed via self-assembly

Cp2Yb·2THF reacts with CpNa in 1：1 molar ratio in THF at 40℃ for 2 h, and the in situ generated anionic divalent complex NaYbCp3（THF）n reacts further with an excess of CpH at 40℃ for 48h, after work-up, affording the trivalent anionic ytterbium complex[Na（THF）2（μ2-η^5-Cp） （η^5, η^5,η^1-Cp3Yb）（THF）]n：（1） by oxidation reaction of Cp2Yb with CpH. Crystal structure determination reveals that complex 1 has one-dimension polymeric chains of distinct Na（THF）2（μ2-η^5-Cp） （η^5, η^5,η^1-Cp3Yb）（THF） units, which were formed by the coordination of the bridging Cp ligand with Cp3Yb＇THF and Na（THF）2 in η^5,η^5 mode via self-assembly.     

Original component of grain size index in core sediment from southwestern slope of the South China Sea and its paleoenvironmental implication

Traditional grain size analysis was basically used to discriminate sediment type based on its particle dimension for sedimentary naming[1,2] and to analyze the dynamic feature of transport medium, including water current and wind strength[3―5]. Recently, some patency advances havebeen made by using different methods to separate different grain sizes in various original composition from sediments for searching a new way of paleoenvironmental study[6―8]. Grain size analysis is even playing an …     

Simulation of a compartment fire using a zone model

This paper presents the zone modeling analysis of a single compartment flashover fire. Two criteria are applied in the model to judge the onset of ignition for different combustibles. By calculating the total received energy through radiation or the surface temperature of the combustible, the fire growth can be quantitatively determined. The improved zone fire model shows the influence of different combustibles upon the fire growth. This model is better than the traditional zone model because the common criteria of flashover, i.e. an upper layer temperature of 600℃ and the heat radiation intensity received by the floor of 20 kW/m^2, have not been applied in it.     

太原市古树名木现状及保护对策刍议

百年以上树龄的树木，稀有、珍贵树木，具有历史价值和重要纪念意义的树木等古树名木，是我国林木资源中的瑰宝，是自然界和前人留下的珍贵遗产，古树名木是历史的见证，活的文物，也是风景旅游资源的重要组成部分，具有极高的科研、生态、观赏和科普价值。做好古树名木的保护工作是全社会长期的、重要的工作。     

从自然农法看循环农业技术的哲学基础

循环农业是中国现代农业发展的重要阶段，循环农业的技术体系是生态化的技术体系，自然农法是生态化农业技术体系的理论基础。自然农法的思想体系以生态整体观、人与自然和谐观和物质循环观为基础，对建构循环农业技术体系，具有深远的现时代意义。     

生态园林城市建设中有害生物的非化学控制

分析了有害生物对生态园林城市建设产生的作用,介绍了生态园林城市建设中有害生物的非化学控制方法,指出发展非化学方法控制城市园林有害生物已渐渐成为目前园林植保的主流。     

New Public Key Cryptosystems from Combinatorial Group Theory

0 IntroductionThe security of most commonly used cryptographicschemesis essentially based onthree families of compu-tational problems :the integer factoring problem(RSAprob-lem) ,the Diffie-Hell man problemand the discrete logarithmproblem,andthe elliptic curve variants thereof .Inthe middleof 1990s , Shor[1], Bonehet al[2]presented some remarkablequantumalgorithms which can solveinteger factoring problemand discrete logarithmproblemover any group including Ga-lois fields and elliptic curve…     

Merkle Tree Digital Signature and Trusted Computing Platform

0 IntroductionDigital signatureis a key technique to provide datainteg-rity andsource authenticationcapabilities to enhance da-ta trustworthiness in trusted computing platform. Most cur-rent digital signature schemes are based on complex mathe-matical problems , such as integer factoring, discrete log-arithm,and discrete logarithm on elliptic curves . The hard-ness of these underlying mathematical problems is really un-certain at present . Merkle treeis a method used for authenti-cation and di…     

A New Watermarking Protocol against Conspiracy

A trusted third party introduced in watermarking protocols would decrease the security and affect the implementation of the protocols. In this paper, a new watermarking protocol with an un-trusted third party （UTTP） was proposed. Based on the idea of all-or-nothing disclosure of secret （ANDOS）, all of the buyer, the seller and the third party didn＇t know the exact watermark, which was embedded in a digital content for tracing piracy. The proposed protocol provided mechanisms to trace piracy and protect customer＇s right. In addition, the problem that a seller colluded with UTTP to frame the buyer, namely, the conspiracy problem, could be avoided.