大数据环境下资源负荷短期预测时间跨度估计

大数据环境下资源负荷短期预测时间跨度计算是提高大数据资源调度和数据集成的基础。通过对大数据环境下资源负荷短期预测时间跨度的准确估计,提高资源负荷的预测性能。提出一种基于非线性差分相点融合估计的资源负荷短期预测时间跨度估计算法。构建大数据环境下资源负荷模型,基于非线性差分相点融合估计的资源负荷短期预测时间跨度估计,进行非线性差分相点融合,进行全网拓扑信息激励传播均衡设计,通过频繁的切换来进行网络选区,将时间划分为连续区间,重新分配大数据环境下的时间跨度,最后得到基于线性差智能群辨识的资源短期预测时间跨度估计算法改进。仿真结果表明,该算法具有较好的时间跨度估计性能,提高了大数据环境下的资源负荷预测精度,具有较小的任务调度路径延时和能耗损失,为提高云平台的资源利用效率提供基础,展示了较好的应用价值。     

云计算系统中数据中心分类区的确定模型仿真

对云计算系统中的漂移数据中心分类区的准确确定,可以提高云计算系统的扩展能力和缓存能力。传统方法采用线性差分智能群识别方法实现中心分类区的确定,导致漂移数据的群辨识效果不好。提出一种基于粒子群聚类的云计算系统中数据中心分类区的确定算法模型,并进行仿真实现。构建云计算系统网络激励传播机制,实现资源负载均衡,把云计算系统的存储数据结构定义为一个四叉树,构建云计算网格环境下空间资源调度框架体系,进行云计算系统的漂移数据特征提取,使得资源负载均衡达到最优值,实现算法改进。实验得出,模型对云计算系统的漂移数据中心分类区确定准确,数据融合精度较高,聚类性好,云计算系统的扩展指数提高13%,缓存执行能力提高20.5%,展示较好的性能。     

嵌入云信息平台双向中继物理层数据传输协议

在嵌入式云信息平台设计中,需要设计物理层数据传输协议优化信息平台的数据调度和任务分配能力。传统的协议采用UDP协议构建云信息平台的中继物理层数据传输协议,产生大量的流量累积,导致物理层拥堵。提出一种基于双向中继负载均衡的嵌入式云信息平台物理层数据传输协议设计算法。构建嵌入式云信息平台的网络模型,对信息平台数据进行压缩处理,通过双向中继物理层数据传输,定义物理层数据传输的调控函数,实现对数据传输的物理层协议构建,实现数据动态分配。实验结果表明,采用该算法,能有效提高数据的传输效率,降低数据传输延时,优化信息传输部署。     

基于边缘逆理论的辨识系统并行查询扩展算法

多源数据辨识系统广泛应用在机载数据辨识控制、大型机械设备故障诊断和云存储系统数据库集成等领域。对多源数据的辨识系统并行查询和数据调度中,因数据的静态非线性测量过程影响了查询效益,需要对辨识系统并行查询链路进行扩展。提出一种基于振幅调节Fourier变换边缘逆理论的辨识系统并行查询扩展算法。进行多源数据辨识系统基本构造和模型设计,提取查询特征信息,采用RBF神经网络系统进行多源数据输入自适应学习,构建神经网络辨识系统的边缘逆向量,采用边缘逆理论进行振幅调节Fourier变换实现多源查询数据的状态重组,实现查询链路扩展设计改进。仿真结果表明,该算法提高了辨识系统的查询通道的链路相位,多源数据调度的时间成本及空间成本大幅降低,加速比提高,算法将在系统状态识别、机械故障智能诊断等领域具有较高的应用价值。     

基于QoS维度分箱的数字化云平台资源置换算法

对数字化信息服务云平台的资源准确置换可以提高云平台的数据预取和资源调度能力。传统方法中对信息服务云平台的资源置换采用边缘逆理论并行查询置换算法,不能满足多媒体数据传输的QoS需求。提出一种基于QoS维度分箱的数字化信息服务云平台资源置换算法,以全局度量为中心节点,进行溯源处理,采用QoS维度分箱的信息特征维度匹配,将乘性噪声相对稳定的一段时间称为一个时隙,实现数字化信息服务云平台资源置换算法改进。仿真表明,该算法通过资源置换处理,提高信息检索的定位准确率,减少资源分配的运行时间,提高云平台的资源调度分配性能。     

突发浪涌数据下差异云平台的弱关联数据调度

突发浪涌数据下差异云平台数据间的关联性破坏概率逐渐增加,降低了数据在冗余环境下查询效率。按照突发浪涌数据下云平台的弱关联数据调度特征,通过基于Apriori的弱关联数据挖掘方法,采集突发浪涌数据下差异云平台的弱关联数据,通过改进离散粒子群算法优化任务节点数字串的编码形式,实现数据调度任务,对粒子位置更新公式进行优化,采用优化离散粒子群算法进行节点寻优,获取最佳调度节点集,实现突发浪涌数据下差异云平台的弱关联数据调度。实验结果表明,该调度方案能够优化云平台资源的使用效率和服务响应时间,提高了总执行效率,节省了云资源,具有较高的节能开销比和用户满意度。     

基于物联网的城轨车辆轮对温度与振动状态智能监控系统研究

轨道车辆的轮对运行状态监测是保障车辆高速运行的重要环节,本文提供了基于无线物联网的车辆轮对实时温度与振动状态智能监控系统解决方案,引入BP与卷积神经网络机器学习算法,利用云平台提供的数据存储与高能运算服务,实现轨道车辆行驶过程中轮对运行状态的实时监控与故障预警诊断。     

移动云接入平台下网络信息云服务稳定性设计

对移动云接入平台下的网络信息云服务的稳定性设计是保证网络运行和服务质量重点。传统的云接入设计算法采用移动通信频分复用算法,当在快速运动空间和自然界中进行云接入信道切换时,云服务的稳定性不好。提出一种基于移动通信节点衰减性能检测的高速移动环境下云接入平台下的网络信息云服务稳定设计方法。预测通信节点接收信号幅值的信噪比,对组合服务进行评价,实现云服务随机相位集成,提高系统稳定性。仿真结果表明,采用该算法能有效实现网络信息云服务稳定性增强,降低系统运行时间,提高系统可靠性,展示了较好的应用价值。     

基于数据链估计和时间窗口重排的坏数据检测

在嵌入式云信息网络平台中,物理层数据传输容易受到外界攻击变异成坏数据,威胁网络安全,传统方法采用最小延时数据聚集算法实现对该类算数据的检测,算法数据的不均匀性和时延性,检测性能不好。提出一种基于数据链距离估计和时间窗口重排的网络坏数据检测算法。进行嵌入式云信息平台构建和数据采集,采用统计信号分析方法对数据进行信息链构建,对数据链距离进行估计,采用时间窗口重排方法对坏数据的谱特征进行空间重组,提高坏数据检测性能。仿真结果表明,采用该算法进行嵌入式云信息网络平台通信传输的坏数据进行检测,准确检测概率提高34.56%,检测算法的收敛性和鲁棒性较好,保证了网络系统安全。     

时频对偶重排网络群攻击频率扩展技术

在网络群攻击模式下,对群攻击信号频率扩展可以达到降低攻击强度、衰减攻击效能的目的。传统方法中,采用时频分析Viterbi算法,计算群攻击信号的瞬时频率值,通过瞬时频率线性扩展的方法,衰减攻击性能。由于损失频率的大小非均匀性,扩展性能不好。提出一种基于Viterbi时频分析算法的群攻击信号频率扩展技术,构建网络群攻击模型,采用时频分析Viterbi算法得到该瞬时谱的瞬时频率。基于频域自适应算法,计算信号的Viterbi时频分析对偶特征,在瞬时频率估计值进行修正,实现频率扩展,得到频率扩展后输出的群攻击信号幅值,通过频率扩展衰减攻击信号的强度能量聚焦。仿真实验结果表明,算法对频率估计精度优于传统方法,网络群攻击频率得到有效扩展,对攻击强度的衰减效果明显提高。     

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.     

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.     

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.     

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."     

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.     

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.     

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.