基于叠加编码的Web网页抓取路径损耗估计

对Web网页抓取是实现Web文本特征数据检索的最佳方式,Web网页抓取路径损耗误差的优化估计可以提高对Web数据的挖掘性能。传统方法中,对Web网页抓取采用基于线性滤波检测的单模匹配抓取方法,受弱信号幅度和临界阈值约束,路径损耗较大,且无法有效实现路径损耗误差有效估计。提出一种基于叠加编码特征统计的Web网页抓取路径损耗误差估计算法。构建Web网页文本特征抓取的目标函数,进行Web网络路径损耗模型构建,设计叠加编码算法进行特征统计,得到Web网页抓取路径概念格。仿真实验表明,该算法能有效提高Web网页抓取路径损耗误差估计精度,进而提高了Web网页文本数据抓取的查准率和文本特征数据的挖掘性能。     

结合蜂群算法与RBF神经网络的软件错误定位方法

软件错误是软件开发过程中经常出现的问题,有效地定位错误能够提高软件开发的效率。通过对软件运行时信息的收集与分析,从机器学习的角度提出了一种将蜂群算法与RBF神经网络结合的软件错误定位模型。首先,利用蜂群算法克服RBF神经网络由于隐层节点中心值随机化而导致的网络性能较差的问题,对RBF神经网络模型进行优化与改进。然后,对程序运行过程中的相关信息进行编码,将此编码作为蜂群神经网络模型的训练数据集。最后,根据虚拟测试集进行软件错误定位,实验过程中选用Siemens Suite套件进行了仿真实验。实验结果表明,结合蜂群算法优化与RBF神经网络的软件错误定位方法在软件错误定位方面能够表现出较好的性能。     

基于半结构化分割的Web热点数据挖掘算法

随着大数据信息技术的发展,数据在线监测和数据挖掘成为计算机信息领域研究的热点。通过对Web热点数据分割挖掘,提高信息热点追踪和Web数据分类能力。传统算法采用非结构化数据挖掘算法,无法有效对Web热点数据进行准确定位和分层挖掘。提出一种基于半结构化分割的Web热点数据挖掘算法。采用半结构化数据进行特征分割,基于优秀基因位进行差分进化,使寻优曲线不断趋于平缓,在多个节点上并行的运行比较脚本,采用半结构化分割,使得Web热点特征挖掘实现自适应寻优,得到Web热点数据的分配因子,提高了挖掘性能。仿真结果表明,该算法获得了良好的效率和精度,提高了Web热点数据挖掘的自适应寻优能力。     

基于免疫算法的RBF网络优化

针对RBF的网络算法有多种,具有固定中心的RBF网络训练算法、梯度下降的RBF网络训练算法、最小二乘的RBF网络训练算法,无论哪种算法,对于求RBF网络隐节点的中心c j和标准参数？2都是比较困难的,如何使网络学习达到要求的精度,本文提出了基于免疫算法的RBF网络优化的改进算法,使隐节点的中心求解较为容易,有利于RBF网络有效的推广。     

网络个性化信息的特征提取研究

网络文本挖掘是从非结构化的文本中发现潜在的、有价值知识的一种有效技术,要使检索到的信息在满足用户个性化需求方面,既具有高准确率又有高回收率,则是一件很困难的事情。为了解决以上问题,在介绍特征提取概念的基础上提出了一个基于遗传算法的Web文本特征抽取算法,该算法进一步提高了Web文本的处理效率。     

基于大数据分析的文本智能识别系统的研究

根据软件工程的基本原理在Ubuntu操作系统环境下使用Eclipse开发工具,设计并实现了基于Hadoop系统架构的NaiveBayes算法文本分类系统。系统将大量中文文本数据集存储在分布式文件系统HDFS上,通过MapReduce并行计算模型和Ansj中文分词库对中文数据集进行分词,采用TF-IDF算法进行文本特征抽取,最后基于Spark并行计算框架和NaiveBayes算法对特征数据集进行模型训练,得到文本分类模型,将文本分类服务集成到Web页面。系统基本实现了文本的正确分类。     

文本数据挖掘技术在Web知识库中的应用研究

介绍了文本数据挖掘和知识提取的基本理论,然后分析了网络信息的检索与挖掘的特征,特别是文本挖掘、Web数据挖掘和基于内容数据挖掘与之相关联的系列问题.在此基础上,分析了Web知识库的设计、建立、文本数据挖掘和知识发现所需的理论和技术,对Web知识库系统的架构和功能模块进行分析和设计,建立了基于文本数据挖掘的Web网络知识库的模型.     

引入或然状态优化控制的网络文本特征挖掘

引入或然状态指数矩阵,对网络文本特征进行指数分离处理和挖掘优化导向性控制,提出一种引入或然状态指数矩阵优化控制的网络文本特征导向性挖掘新技术。对具有或然性的文本数据进行分离修补导向性挖掘聚类,在文本数据择取过程中,将不同文本分量元素进行初始化倾向性分类处理,由指数矩阵确定元素属性类别概率,从而确定多个导向性聚类中心,从而实现了对或然网络文本特征的准确挖掘。仿真实验表明,新的挖掘技术能有效提取到模凌两可的或然性弱聚类导向性分类特征,数据挖掘准确率达到99.97%,而传统方法是根本无法对这类文本特征进行有效挖掘,展示了算法的优越模糊数据处理价值。     

一种基于“特征降维”文本复杂网络的特征提取方法

【目的/意义】本文构建一种“特征降维”文本复杂网络进行文本表示,解决传统词同现文本复杂网络处理海 量数据时的维数灾难与语义不足问题,再结合机器学习方法提升文本特征提取效果。【方法/过程】依据共现关系抽 取二级词条,再结合依存句法关系抽取三级词条,构建“特征降维”文本复杂网络,接着利用PCA算法和TOPSIS法 评价网络节点重要性提取反映文本主题的关键词作为文本特征词,实现文本特征提取。【结果/结论】本文以网络新 闻数据为实验对象。实验结果表明,特征降维文本复杂网络能较好地表示中文文本,并且在较好地保留了文本语 义信息的同时有效减少网络节点冗余,结合PCA算法的特征提取方法可以使文本分类性能提高。     

脉冲响应不变解卷积Web数据奇异特征挖掘

针对Web数据奇异特征挖掘时,信道对奇异特征具有卷积效应,影响特征挖掘精度。提出一种脉冲响应不变解卷积算法,实现对奇异特征对的盲解卷积,提高奇异特征挖掘性能。利用Web数据奇异特征的时间可预测性作为盲解卷积的解卷测度,采用脉冲响应不变算法对基于该测度的代价函数进行优化求解,从而成功得到解卷积滤波器系数,实现对Web数据奇异特征的盲解卷积。仿真实验表明,采用该算法挖掘Web数据的奇异特征,对于奇异特征信号具有很好的盲解卷积效果,所挖掘的奇异特征相关系数和重构信噪比均较高,特征挖掘聚类性好。     

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."     

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.     

Stern-Gerlach effect goes chiral

Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms＇ spin states （Phys. Rev. Lett. 99 130403）.     

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.