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遥感图像采集过程中,经常受到天空外在因素的不定干扰,云层或者大气污染会大幅反射遥感射线,造成遥感图像特征不清晰、特征丢失,导致传统的图像定位算法很难对这种随机性的外界干扰建立有效的特征提取模型,造成定位偏差较大。为此,提出了一种基于约束领域小基团特征的遥感图像定位算法。通过有效地提取特征,运用约束方法对特征进行领域划分,在划分结果内提取像素基团能量特征。运用能量特征消除外界干扰对特征模糊的影响。实验结果表明,这种算法能够有效提高遥感图像特征定位的准确性。 相似文献
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传统的Canny边缘检测方法提取遥感图像边缘视觉特征在设定不变矩阈值采用经验模式,导致视觉提取分辨率不好,特征提取不准。提出采用Morlet小波变换对遥感图像边缘特征进行不变矩阈值函数构建,提出一种基于Morlet小波Canny边缘检测算法的遥感图像视觉特征提取。将图像数据经过Canny边缘检测和标记分水岭分割,实现遥感图像视觉提取。仿真实验表明,该方法在遥感图像视觉特征提取上比传统的Canny边缘检测方法效果明显,提取正确率最高可以达到94.20%,算法将在远距离遥感目标识别和监测等领域具有很好的应用价值。 相似文献
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本文提出了改进的Harris算法与SUFT算法相结合的图像匹配方法,用稳定的SUFT算法检测提取尺度空间极值点作为特征候选点,根据灰度的"相似度"的原则进行Harris特征提取,实验结果表明,使用改进后的算法进行遥感图像配准能有效去除误配点,使候选点数量更少,特征点更稳定,使得匹配的效率更高,准确性更高。 相似文献
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《科技通报》2015,(12)
遥感图像中存在大量微小红外目标,对其准确的分类和定位识别是实现远程目标识别和遥感测量的基础。目前对该类红外小目标的识别方法采用单层正方形网格生成方法,对随机标定的红外目标点的识别效果不好。提出一种基于Harris角点检测的遥感图像中微小红外目标的分类定位识别算法。构建遥感图像的红外目标数据采集模型,对图像进行角点特征提取预处理,采用Harris角点检测算法实现对红外目标微小特征点的信息标定,实现对其准确分类定位。仿真实验表明,采用该算法进行微小红外目标的分类定位识别,具有较高的准确性,对红外目标的特征提取和定位识别效果较好,在远程目标探测和遥感监测等领域具有较高的应用价值。 相似文献
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基于TM遥感影像的玉米地专题信息自动提取 总被引：1，自引：1，他引：1
TM遥感影像中专题信息的自动提取是目前遥感界的研究热点，也已成为遥感信息生产流程中的瓶颈环节。本文分析了耕地专题信息自动提取的研究现状，选取了吉林中部和辽宁省东北部作为研究区，采用监督分类的方法对研究区TM遥感影像进行分类，提取了玉米地专题信息，玉米地信息的提取精度为85.5%。根据遥感影像目视解译的原理，提出了基于多特征空间的遥感影像专题信息自动提取的研究方法，通过对多特征空间的数学描述和计算机处理实现
遥感专题信息的自动提取。采用多特征空间的方法将玉米地信息分为光谱特征空间、形状特征空间、区域地学特征空间和干扰特征空间，应用ERDAS8.5遥感图像处理软件中的knowledge engineer模块的开发功能，设计了基于多特征空间的玉米地专题信息自动提取的专家库，使用专家库对玉米地信息进行了自动提取，提取精度为92.9%。从基于多特征空间的分类结果与监督分类结果的比较发现，基于多特征空间的自动提取方法可以提高专题信息的提取效率，对未来实现遥感影像的智能解译是一种研究方法的探索。 相似文献
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《科技通报》2015,(10)
在不同光照和旋转角度下进行地理特征遥感识别是测绘领域的难点,为了实现对地理地形的准确测绘,需要进行地理特征遥感识别优化设计。传统方法中,采用遥感图像边缘特征检测算法,当遥感图像出现旋转角度时,识别性能不好。针对这一问题,提出一种角点检测的地理特征遥感识别算法,并进行系统设计与实现,系统通过图像传感模块采集遥感图像,经过角点特征处理器提取图像特征。在不同光照和旋转角度,采用单尺度Harris角点检测算法对图像进行检测并提取角点,得到地理遥感特征数据采集的角点模型,基于角点检测,进行遥感识别算法改进和系统实现。实验结果表明,采用该算法和系统,地理特征遥感识别准确率高,耗时较少,提高对地理特征遥感识别性能。为实现对地理地形的准确测绘提供依据。 相似文献
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图像检索为数字图书馆的发展提供了技术支持,图书馆应重视数字化发展以提升服务质量。本文提出一种数字图书馆图像资源检索框架,并对系统的实现过程做了详细的分析。同时,在提取图像特征时提出了一种基于非下采样的Contourlet变换图像检索算法（NSCT）,能够在大量图像数据中挖掘有效的特征信息。该算法首先对图像进行多尺度、多方向分解,然后计算低频和高频中不同方向的子带系数的标准差和均值作为图像的纹理特征。实验结果显示,本文提出的图像检索框架具有可行性,能够为用户提供更优质的搜索服务,并且与同类特征提取算法进行比较,该算法具有良好的检索性能和较高的查准率、查全率。 相似文献
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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
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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
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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
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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
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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
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《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
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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
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《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
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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
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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