共查询到20条相似文献，搜索用时 62 毫秒
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重点讨论了图像分割法中的阈值研究法,包括全局阈值法和自适应阈值法。对全局阈值算法中的人工选择法、迭代式阈值选择法、最大类间方差法以及自适应算法中的分水岭算法进行了重点分析,用M atlab进行实现并给出了实验结果;分析了几种算法的适用情况,并提出了一些改进意见。 相似文献
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车道检测系统中的关键问题是图像分割,而图像分割的基础则是自适应阈值的确定。本文针对车道检测系统对比了不同的自适应阈值算法,并采用物理模型仿真的研究方法简要分析了这几种算法的特性,最终确定了一种各项性能指标均较优的自适应阈值算法。 相似文献
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在无线传感网络簇内节点数据自适应数据压缩和分布式数据处理过程中,由于信息熵是一种基于信息表现特征的统计形式,通过熵融合可以提高数据汇总量,由于融合的上下限阈值具有不确定性,因此需要进行自适应阈值寻优,实现冗余数据过滤。提出一种基于相异粒度自适应阈值寻优的熵融合算法,对簇内二维信息熵进行最大寻优,进行簇内数据熵融合网络模型的构建,对簇内数据相异粒度自适应阈值寻优,剔除边缘异常数据,采用遗传算法进行数据布局,充分考虑了数据本身特性和网络因素,降低个体对适应度函数的灵敏度,使寻优曲线不断趋于平缓,调整粒子相异粒度之间的速度和位置,得到簇内数据的自适应阈值寻优熵融合结果。实验结果表明,该算法能实现融合阈值的自动寻优,滤除异常数据,搜寻有关信息熵的最大值,在冗余判定、数据传输延迟影响等问题研究中具有较大的应用价值。 相似文献
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针对复杂交通场景中运动车辆检测方法存在的局限性,本文提出了一种基于中值模型和自适应阈值的运动检测算法。利用自适应阈值对差分图像的三个颜色通道进行二值化处理,实现了运动目标的精确检测,采用中值更新策略实现背景图像的实时更新。实验结果表明,算法可以从复杂交通场景图像序列中有效地检测出运动目标,且算法计算量小,具有良好的鲁棒性与实时性。 相似文献
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基于包络特征的网络流量预测阈值调控算法 总被引：1，自引：0，他引：1
《科技通报》2015,(10)
对网络流量序列的准确预测的基础是进行流量判决门限阈值的合理调控,为了提高网络流量预测的精度,进行阈值调控优化设计。传统方法采用流量序列调频估计的方法进行阈值调控,算法不能准确估计流量序列的包络特征,预测精度不好。提出一种基于包络特征的网络流量预测阈值调控算法。通过不同类型的网络设备进行流量采集终端联网构建,采用自相关特征奇异分解对流量序列进行线性特征叠加运算,构建网络流量预测的时间序列模型。采用统计学数学方法对流量序列的延迟时间互信息进行阈值调控自适应建模,提取流量序列的包络特征。实现对网络流量预测的阈值调控,提高预测精度。仿真实验表明,该算法能实现对流量预测阈值的自适应调控,预测精度较传统方法提高37%,性能优越于传统算法。 相似文献
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为了解决心电图QRS波检测的问题,研究了一种基于自适应小波变换来检测QRS波的算法。该方法用心电信号的小波变换作为自适应白化滤波器的输入,然后对白化滤波后的输出进行匹配滤波和阈值检测来识别出QRS波。采用该方法,有利于减小检测的误检率以及提高运行速度。 相似文献
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本文基于小波阈值去噪的基本理论,提出了一种基于Context模型的自适应小波去噪算法。该方法利用Context模型建立图像小波变换后的系数分类模型并根据分类使用不同的阈值去噪。实验结果表明本文提出的算法无论是PSNR值还是视觉效果,都大大优于传统算法。 相似文献
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视觉技术已经广泛地应用于智能车巡航系统中,其中图像处理是提取道路信息的重要途径,而图像阈值是其中一个重要的参数。文章提出一种自适应图像阈值的算法,解决了在实际环境中,由于受到光线等因素影响而带来的阈值变化,实验证明效果良好。 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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《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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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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《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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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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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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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