基于云计算循环加密的服务器响应效率优化

研究在云平台环境下的网络交互数据优化加密技术以提高云计算服务器的响应效率,降低服务器响应时间。传统方法采用行为子网络动态密钥构造模型实现云计算循环加密,无法有效满足用户在Possion分布下服务器响应效率。提出一种基于云计算循环加密的服务器响应效率优化算法。构建云平台环境下的网络数据交互模型,采用云计算速度调节动态优化技术提高服务器的响应效率,采用码元频数检测的加密和解密方案,构建云平台环境下的数据交互节点拓扑模型,根据节点剩余度规则,得到后代节点失效过载比,通过部分链路失效多路径加密方法使得数据聚集具有很高的容错功能,进而提高服务器响应效率。仿真实验表明,算法具有较好的数据加密准确性,该方法能有效缩短云计算服务器响应时间。     

面向决策树目标路径编码的相空间嵌入维优化

提出一种面向决策树目标路径编码的相空间嵌入维计算优化算法。构建云平台环境下的数据交互节点拓扑模型,通过部分链路失效多路径加密方法使得数据聚集具有很高的容错功能,然后采用决策树目标路径编码方案,在给定带宽约束和量化阈值的情况下,对决策树目标路径编码的相空间嵌入维数据进行自适应的量化分解,以实现对决策树目标路径编码的相空间嵌入维的准确估计,降低误码率。仿真结果表明,该算法能准确估计相空间嵌入维,提高估计精度,能有效降低误码率,提高数据动态交互通信的准确性,信号保真度较高。展示了其优越性和较好的应用价值。     

云存储系统中隐私保护数据的抗泄露加密算法

混沌映射加密算法,虽然能够对数据进行加密,防止数据泄露,但是针对具有非线性属性的隐私保护数据进行加密时性能差,导致数据泄露。为此提出了一种新的基于可撤销多重循环控制的云存储系统中隐私保护数据的抗泄露加密算法。通过分析云存储系统中的隐私保护数据的数据结构模型,进行隐私保护数据的数据编码序列分析,并设计了云存储系统中隐私保护数据的线性编码和密钥。引入可撤销多重循环控制方法,实现云存储系统中隐私保护数据的抗泄露加密算法的改进,在整个过程中保证了数据的保密性。仿真结果表明,该算法进行云存储系统中的隐私保护数据的抗泄漏加密,数据的密钥编码分布的随机性加强,降低了被破译概率,降低了数据泄露风险,提高了数据加密的隐私保护性能。     

基于码元频数检测的比特序列加密算法

采用随机性码元频数检测的方法实现对链路层加密数据的识别,提高随机性码元频数检测识别率。传统方法采用随机抽样的比特序列加密方法,加密与未加密链路层出现混同,加密性能不好。提出一种基于随机性码元频数检测的比特序列加密算法。构建随机性码元频数检测保密通信系统,建立随机性码元频数比特序列模型,选择分块长度作为分块长度目标值,求解发送端随机性码元频数比特序列加密的时延,进行码元频数检测,实现比特序列加密算法改进。获得足够泛化性能的控制密钥,提高承载信息信号所引起的随机性码元频数比特序列的抗噪性能。仿真结果表明,采用该算法,能有效提高对未加密数据的识别率,提高识别结果的可信度,展示了较好的应用价值。     

基于二叉树偏码匿名乱序的云平台协同计算研究

针对传统的云平台协同计算中,顺序数据存取过程安全性差的问题。提出一种基于二叉树偏码匿名乱序的云平台协同计算方法。建立匿名乱序的云平台访问模型,对用户数据进行加密,构建访问权限控制系统,将用户数据与用户信息分离;利用二叉树偏码匿名乱序的方法对用户数据进行存储,在云平台中,用户通过签名密钥实现用数据的控制,云平台只负责数据的存储,从而保证了用户隐私的安全。仿真实验结果表明,改进算法能够保证用户的信息安全,从而提高了云平台计算的服务质量。     

基于混叠谱跨层补偿的语义网检错码深度加密

通过对语义网中的检错码加密设计提高网络用户的文本隐私保护能力。传统方法采用多元线性回归分析的检错码加密算法,由于检错码自身的数据扰乱导致加密性能不好。提出一种基于混叠谱跨层补偿的语义网检错码深度加密算法,对特征数据进行预处理,形成符合特征关联的输入数据形式,进行混叠谱跨层补偿。对不同特征的数据进行混叠谱跨层补偿挖掘处理,形成特征判决规则库,基于CSBDLP公钥加密协议进行多元线性回归隐私保护,得到语义网检错码加密协议密文矩阵,实现了基于混叠谱跨层补偿的语义网检错码深度加密算法改进,提高了检错码加密的深度和数据容量。仿真结果表明,该算法具有较好的语义网检错码加密性能,加密深度较高,深度越深,解密所需要花费的时间越长,从而保证了算法的加密优越性能,研究成果将在语义网构建和数据加密及隐私保护中具有重要的应用价值。     

云数据隐私侵权风险与矫正策略

云数据自云端形成至完全销毁的完整生命周期中,时刻面临着云服务商和公权机关侵害数据保密权、支配权、知情权等诸多风险.通过构建云环境标准体系、云隐私影响评估制度、云数据隐私法律保护框架、云服务协议的数据隐私保护条款、侵权赔偿幅度与专门监督制度等,矫正恶意侵权人利益驱动与规则缺失联合作用导致的机会成本过低的畸形状态,寻求云环境高效运转与保护云数据隐私之间的动态平衡.     

物联网环境中占用空间较小的隐私保护加密算法研究

在物联网环境中,传统的加密算法对隐私保护进行加密时,由于数据量比较大,造成数据进行加密时造成的占用空间较大的现象。提出基于Baptista隐私保护混沌的加密算法。采用椭圆曲线的加密方法进行一次加密,能有效地提高安全性能,降低计算的复杂度,利用Baptista隐私保护混沌的加密算法进行二次加密,依据S盒混沌掩码的技术对Baptista混沌的密码进行增强,设计适合物联网的加密系统,依据应用的数据需求对数据传输的安全级别进行预置,有效地克服了传统方法存在的弊端,提高了加密算法的安全性,降低了数据的占用空间,利用Baptista混沌的二次加密完成对物联网环境中占用空间较小的隐私保护加密算法的研究。实验的结果表明,所提算法能有效地降低数据加密过程中的占用空间。     

云计算中数据的隐私保护数据加密算法研究

随着云计算中大数据的广泛应用,得到的数据量呈指数级增长,从而导致用户数据隐私保护方面面临严峻的挑战。数据加密的执行时间长度一直是数据加密处理和传输过程中的重要问题之一。在实际应用中许多应用程序为了达到整体数据传输性能水平的提升都放弃了数据加密。针对移动云计算中用户数据的隐私保护问题,本文提出一种新的数据加密方法,称为选择性数据加密算法(SDEA)。该算法原理为在单位时间限制下使用不同的隐私分类方法选择性地加密数据,目的是通过在实际应用最少的执行时间要求内使用选择性数据加密算法来最大化对大数据的隐私进行保护。仿真实验结果表明,本文提出的移动云计算中大数据的隐私保护数据加密算法兼顾数据传输效率的同时具有良好的数据隐私保护性能。     

基于0-1游程频数检测的链路层加密数据识别

链路层加密数据的识别是进一步开展网络安全防护和协议识别的前提,当前方法主要是对流量所属的上层协议类型进行加密数据识别,采用混合多级的加密流量识别方法,对链路层加密数据的识别性能欠佳。提出一种基于0-1游程频数检测的链路层加密数据识别算法,采用随机性检测理论,进行链路层数据加密解密方案设计,构建标准正态分布函数的统计量对比特序列进行码元频数检测,实现0-1游程频数检测算法。实验表明,该算法能有效解决链路层块内频数检测过程中的分块长度选择及对加密数据识别率低的问题,链路层加密数据准确识别率提高显著,在网络保密数据传输等领域具有很好应用价值。     

Low doses of a red wine ingredient figh diabetes in mice

Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.     

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.     

Molecular motor assembly of a biomimetic system

Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.     

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.     

To serve and promote science development via innovation

CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.     

Tracing the origin and early radiation of birds——Paleornithologist ZHOU Zhonghe

With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."     

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.     

The Information Environment and Universal Service

This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment.     

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.