共查询到20条相似文献，搜索用时 187 毫秒
1.
2.
设计了一种在线电能质量扰动(power quality disturbance,PQD)识别方法.该方法应用小波分解对各种扰动进行特征提取,应用数据挖掘技术中的决策树算法对扰动进行分类.为了在线应用,采取了一种滑窗模型对PQD别进行设计.这种设计方法具有记忆和运算时间短的优势,在识别PQD时能做到识别准确率高并且消耗时间短.通过仿真实验结果证实了该方法的有效性. 相似文献
3.
目的:自美国将CPS的发展列为重点研究项目,引起了各国广泛的关注。不同于传统的系统,在通信方面,CPS融合了大量的异构网络,其规模远大于现有的控制网络。为提高对协议识别的效率和准确度,并对其进行分类,系统中大量数据传输带来的网络拥堵是我们要解决的主要问题。方法:基于网络流的特征,提出了对协议进行识别的变精度粗糙集的权值计算法和决策构造优化算法。结果:基于变精度粗糙集算法协议识别算法,其准确率可达98.7%。结论:基于变精度粗糙集的决策算法相较于普通决策算法,其识别准确度更高、更容易实现。 相似文献
4.
5.
传统算法进行驾驶员疲劳驾驶识别,无法避免由于图像质量较差造成的眼睛瞳孔位置和直径无法确定的缺陷,降低了驾驶员疲劳驾驶识别的准确率.本文提出了一种基于眼睛与面部表情关联性算法的驾驶员疲劳驾驶识别方法.提取驾驶员眼睛与面部表情特征,计算驾驶员眼睛与面部表情特征关联性概率,克服了传统算法的弊端.实验表明,这种算法能够提高驾驶员疲劳驾驶识别的准确率,取得了令人满意得效果. 相似文献
6.
作者运用Nida的翻译理论,分析和讨论科技英语的短语翻译与写作。文章从短语的表层对等翻译,短语的修辞对等翻译和短语的深成对等翻译三个层面讨论了科技英语的短语翻译与写作。Nida的翻译理论对科技英语短语的翻译和写作产生了重要的影响,并对科技英语短语的翻译和写作提供了大量的方法和标准。 相似文献
7.
传统的数字识别算法存在识别速度、识别准确率和识别方法复杂度三者无法兼顾的问题,为解决该问题,提出了基于特征矩阵的高效数字识别算法。该算法首先在预处理的基础上获取字符的特征矩阵,然后用特征矩阵对字符的特征横线、竖线等特征进行提取,最后利用结构语句识别的方法实现数字识别。实验结果表明,基于特征矩阵的高效数字识别算法思路简单、速度快,且识别率达97％以上。 相似文献
8.
介绍命名实体识别在文本信息处理领域的重要地位,分析了中文命名实体识别存在的困难,介绍中文命名实体识别的一般过程、评价标准及方法。提出了一种在构造内部规则和外部规则的同时采用概率统计的中文命名实体的识别方法,并利用这种基于规则和统计相结合的方法。实验证明该方法获得了较高的准确率和召回率,具有可行性和合理性,同时也指出了它的局限性。 相似文献
9.
在电器漏电时,电火花闪动时间过短,捕获特征极难,电火花颜色特征在捕获过程中很容易发生图像帧差错位,造成特征模糊。传统算法是基于电火花颜色特征进行电器漏电识别的,一旦电火花闪动时间过短,将造成电火花颜色特征模糊的缺陷,导致电器漏电识别准确率降低。为此,本文提出了一种基于图像灰度类内方差算法的电器漏电识别方法。利用灰度类内方差方法进行图像灰度特征提取,计算电火花变化系数,从而完成电器漏电识别。实验结果表明,这种算法避免了由于电火花闪动时间过短造成的电火花颜色特征模糊的缺陷,提高了电器漏电识别的准确率。 相似文献
10.
针对当前车辆识别算法,由于传统的特征提取车牌识别方法,直接通过图像的灰度特征进行车牌识别,当外界光线不足时,图像灰度特征不明显而不能准确识别相似字符,造成车牌误识别的问题.提出了一种改进的神经网络算法的车牌识别系统.通过建立汉字网络、字母数字网络找出相似字符之间的差异进行识别,实验表明,这种识别算法实现简单,识别准确率高. 相似文献
11.
A research 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 in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
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.
《中国科学院院刊(英文版)》2008,22(1):2-3
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
13.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
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
14.
《中国科学院院刊(英文版)》2008,22(1)
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
15.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US 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 the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
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
16.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
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
17.
Active biological molecules 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 therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
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
18.
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
19.
Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
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.
Puay Tang 《The Information Society》1998,14(1):19-31
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