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1.
何建民  张义 《情报科学》2012,(8):1147-1150,1166
网络社区热点话题识别是监测与引导网络舆情的关键问题,本文针对该问题,通过分析热点话题的属性特征和应用离差最大化、类熵距离法,计算出各属性的权重和话题的正熵、负熵及优劣度,并据此对话题进行排序,找出热点话题。最后经实证验证该方法是合理有效的,所得结果可作为政府监控网络舆情的依据。  相似文献   

2.
网络热点话题检测与跟踪已成为舆情分析领域的前沿研究课题,具有广阔应用前景。本文研究基于主题演化图的网络论坛(BBS)热点跟踪问题。在采用共词分析和bisecting K-means聚类算法检测BBS热点话题基础上,提出了一个综合考虑话题帖子篇数与帖子热度的热点话题关注度计算方法。然后给出了一个基于相对熵的热点话题语义距离计算方法。最后通过构造主题演化图实现BBS热点话题的自动跟踪。在由实际BBS论坛数据构成的测试集上的实验表明,本文提出的方法是有效的。  相似文献   

3.
[目的/意义]学术社交网络吸引了众多科研人员参与并使用,对学术社交网络中的学科交互研究有利于促进科研人员利用学术社交网络开展非正式交流及跨学科合作。[方法/过程]文章以ResearchGate(RG)为例,将iSchool成员机构作为研究对象,获取61所iSchool机构成员用户的交互关系数据,并对其中的2798所机构及其间所形成的30393条交互关系数据进行社会网络分析。[结果/结论]从交互数量来看,iSchool成员机构在学术社交网络中的学科交互范围较广,但跨学科影响力有限,其跨学科交互情况反映了目前图情学科领域的跨学科研究趋势和研究热点;从交互关系网络来看,iSchool成员机构整体学科交互关系网络结构较为松散,网络还呈现出iSchool成员机构分别主要与人文与社会科学类和工程与技术科学类的机构产生交互关系的两种趋势。此外,对学术社交网络中交互关系的拓展和学术影响力的提高有利于科研合作的开展和学术声望的提升。  相似文献   

4.
【目的/意义】近年来移动社交网络的高速发展推动了学术界对网络舆情的关注,网络谣言作为其中的重要 组成部分越来越受到监管部门的关注。本文通过建模仿真对谣言传播群体动态演化特征进行分析,以期为有关部 门有效应对和控制移动社交网络谣言提供借鉴。【方法/过程】本文以经典SIR模型为基础,加入移动社交网络用户 数量等影响因子进行优化,并结合传播动力学理论构建了移动社交网络谣言传播的参与群体动态演化模型,最后 使用MATLAB等软件实现模型和数值仿真。【结果/结论】实验结果显示:谣言在前期发展阶段的传播速度最快,杀 伤力也最大;移动社交网络环境对谣言传播有促进作用;网络容量越大,谣言传播的范围越大;本文模型通过仿真 验算,证明可以用于对移动社交网络环境下的谣言传播进行仿真。  相似文献   

5.
[研究目的]为实现网络热点话题的在线检测,提升增量式聚类算法的聚类效果,提出了基于组合相似度的动态聚类算法,同时通过计算词熵实现主题词提取和演化跟踪。[研究方法]通过CIFG-BiLSTM-CRF模型实现文本的命名实体识别,计算文本与话题的实体相似度,再取文本词向量与话题中心余弦相似度的最大值作为词向量相似度,二者结合判断文本所属话题。在聚类过程中利用时间窗口策略实现话题中心和成员文本的动态更新。同时,计算文本词熵,生成话题的词熵和列表,实现话题主题词提取和演化跟踪。实验以新冠疫情新闻为数据实现话题在线检测,并展示了话题主题词的演化和跟踪过程。[研究结论]实验表明,与传统相似度计算方法相比,组合相似度能够获得更好的聚类效果,聚类过程中提取出的话题主题词也正确地反映了原始数据的热点话题内容。  相似文献   

6.
[目的/意义]利用知识图谱构建大数据驱动的社交网络舆情事件主题图谱,是网络舆情学术界和产业界关注的新问题,结合校园突发事件网络舆情进行可视化分析对推动社交网络舆情监控平台的构建具有一定的理论和现实指导意义。[方法/过程]文章在对知识图谱、社交网络舆情事件主题图谱相关理论进行分析梳理的基础上,构建校园突发网络舆情事件主题图谱中的实体、关系和过程模型,并结合"北京交通大学实验室爆炸"舆情事件进行可视化分析。[结果/结论]数据结果表明,政府官微在舆情引导中起到重要作用;可以从"故事线"和"时间线"两个方面对舆情事件进行可视化分析;高校舆情事件在爆发初期、事件调查进展期、事件调查结果期呈现不同的情感倾向;高校舆情事件的传播媒介在移动端和非移动端传播差异不大;舆情夜间传播活跃度高于日间。  相似文献   

7.
传统数据挖掘方法对数据挖掘时必须为高速通信网络,而且还导致系统响应时间延长,对数据安全性产生威胁。文中以分布式环境为背景,提出基于熵值思想的聚类挖掘改进方法,实现网络多层次数据挖掘。设定网络多层次数据聚类参数,计算产生新聚类数,将该数据值作为聚类搜索范围的上限值kmax,选取合适的有效性Silhouette指标,结合最大最小距离理论设置的聚类中心,获得最佳聚类数目;运用熵值理论及动态规划思想形成改进聚类挖掘方法,运用熵值理论判定数据属性权重值,并获取多层次数据对象与邻近数据间的权重关系,将欧氏距离当作数据相似度衡量依据;利用动态规划思想计算获得最大k个数据对象,确定多层次数据挖掘聚类中心。实验证明,利用文中改进数据挖掘方法可有效挖掘网络多层次数据中的有价值信息。  相似文献   

8.
陈培友  侯甜甜 《情报科学》2019,37(5):115-120
【目的/意义】社交网络平台的普及应用使得传统网络舆情升级为社交网络舆情,舆情风险预警难度进一步 增大,积极探索科学有效的舆情预警新方法对于舆情风险导控而言意义非凡。【方法/过程】在对社交网络舆情自身 特点及其风险预警相关主体进行总结与分析的基础上构建包含多主体影响因素的社交网络舆情风险预警体系,并 综合运用网络层次分析法与灰色模糊评价法构建基于ANP—灰色模糊的社交网络舆情风险预警模型,继而以“重 庆公交坠江事件”进行实证分析。【结果/结论】结果表明:该事件的风险预警等级介于严重和特别严重之间,存在较 大的舆情风险,采用此方法能够实现社交网络舆情风险的有效预警,从而较好地说明了该预警方法的科学性和准 确性。  相似文献   

9.
陈艳 《现代情报》2013,33(11):65-68
本文通过文献调研和网站调研发现,在"人人、新浪微博、豆瓣和微信"这4类社交网络上的图书馆用户数量较多,且读者活跃度较高。本文通过分析这4类社交网络的用户体验、搜索效果、信息传播的特点,以期得出"信息——载体"两者的主要匹配关系,为图书馆信息收集和发布提供一些参考和借鉴。  相似文献   

10.
【目的/意义】社交网络舆情监管关乎社会稳定,区块链作为当前一种重要的应用技术,关于区块链社交网 络的信息传播特征和规律研究将有利于对区块链社交应用的舆情监管提供一定的理论依据。【方法/过程】基于区 块链和信息传播理论,通过爬虫采集区块链社交网络应用数据,采用社会网络分析法,利用Gephi进行数据可视化 并利用统计分析软件进行数据处理。在此基础上,对整体网络下的社群进行对比分析,重点讨论了声誉分与用户 度的关系情况。【结果/结论】区块链社交网络为无标度网络;社群间的平均聚类基本一致并且较低;用户发帖量服 从幂律分布;声誉分高的用户在区块链网络中的影响力较大,其在舆情网络信息传播过程中起着重要的作用。【创 新/局限】基于区块链社交网络应用,本文分析了区块链整体社交网络及区块链社群网络的舆情信息传播特征及规 律,后续将采用动态网络、超网络方法对区块链网络舆情信息传播特征及规律进行分析研究。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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."  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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