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人脸识别在身份验证领域得到了越来越多的应用。本文设计了一种基于LDP特征的人脸识别方案,首先将人脸图像与8个方向的Kirsch模板作卷积,对卷积结果进行二进制编码,得到LDP编码图像,并对编码图像分块提取直方图构建特征向量,采用最近邻分类器和卡方距离,在ORL标准人脸库上进行实验,实验结果表明,选择合适的参数,本文的算法在ORL标准人脸库上的识别准确率最高可达97.85%。 相似文献
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研究基于图像的人脸准确识别问题.人在佩戴眼镜的情况下,脸部受到眼镜遮挡,造成无法提取眼部区域特征,人脸主要特征丢失,造成识别准确率下降.为了避免上述缺陷,提出了少量特征相关性计算的人脸识别方法.对提取的人脸图像少量的特征参数进行非线性变换处理,获取特征向量权值系数.利用小波变换方式计算人脸特征相关性系数,通过少量特征相关性进行人脸识别.实验证明,这种眼部特征图像人脸识别方法提高了佩戴眼镜情况下,人脸识别的准确率,取得了满意的效果. 相似文献
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提出了一种基于稀疏分解的不同光照和姿态的人脸识别方法。通过给定的样本为每一类人脸图像训练一个特定的字典,使得在稀疏限制条件下,图像的表示误差最小。将测试图像投影到每一个字典的原子所形成的空间,然后利用误差向量进行分类。为了处理不同光照和姿态问题,采用了基于反照率估计的姿态的重照技术产生同一个人的不同光照条件下的多幅正面图像,从而使得本文方法能够在只有极少数训练图像的条件下获得很高的识别率。通过采用公用数据库中的人脸图像进行验证表明本文方法能够有效的实现不同光照和姿态条件下的人脸识别,其在性能方面比现有大多数方法更优。 相似文献
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在MATLAB环境下,取ORL人脸数据库的部分人脸样本集,基于PCA方法提取人脸特征,形成特征脸空间,然后将每个人脸样本投影到该空间得到一投影系数向量,该投影系数向量在一个低维空间表述了一个人脸样本,这样就得到了训练样本集。同时将另一部分ORL人脸数据库的人脸作同样处理得到测试样本集。然后基于最近邻算法进行分类,得到识别率,接下来使用BP神经网络算法进行人脸识别,最后通过基于神经网络算法和最近邻算法进行综合决策,对待识别的人脸进行分类。 相似文献
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局部保护投影(LPP)算法属于无监督的算法,仅仅考虑到人脸图像的全局特征,针对LPP算法的局限性,提出了一种加权分块局部保留投影的人脸识别方法。首选把所有人脸图像训练样本分割成相等且不重叠的子图像,并将位置相同的子图像聚集起来,然后对每个子图像集分别应用LPP算法,接着结合信息熵权函数计算各子图像集相应的权重。实验证明该算法的识别率相对于传统的LPP算法具有一定的提高,能够较好地克服光照、表情和姿态变化的影响。 相似文献
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针对传统考生身份认证方法的缺陷,提出一种基于人脸识别的考生身份认证系统。首先利用图像采集系统采集考生人脸图像,然后对人脸图像进行特征提取和特征选择,并将人脸特征输入到人脸特征库进行匹配,最后采用支持向量机算法对人脸进行分类识别。实验结果表明,该系统提高了考生身份识别的正确率,减少了识别时间,能够很好满足实际考试的要求。 相似文献
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由于姿态、光照、表情、遮挡等变化引起的面部特征变化仅出现在整个图像的局部区域中,使用整体图像进行特征提取和识别的传统人脸识别方法效果不佳。为解决上述问题,提出了一种融合子图分割和多类支持向量机的人脸识别方法。首先,将人脸图像分割成多个不重叠的子图像;然后采用广义二维Fisher线性判别分析对每个子图像和整体图像进行局部和全局特征提取,并使用SVM做为图像分类器;最后,通过融合各个SVM分类器的决策给出人脸识别结果。在ORL人脸数据库上对所提出的SD-MSVM方法进行了灵敏度、特异度和K折交叉验证测试,实验结果表明,新的SD-MSVM方法各项指标均优于传统的全局特征提取方法。 相似文献
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表面的纹理特征常被用于目标的识别。这种特征被广泛的应用于各个领域,比如基于纹理特征的人脸识别系统、监视、身份识别等。局部二值模式纹理特征方法(LBP)是最成功的基于纹理特征的人脸识别方法。由于LBP的巨大成功,出现了许多LBP的变异方法,比如多层LBP、中心对称LBP、主LBP等。本文的主要目的在于研究各种LBP的变异方法在人脸识别中的有用性。同时本文还评估了各种实际问题,比如光照变化、旋转、人脸图像表示的变化等在不同LBP人脸识别方法中的影响。基于实际人脸图像数据库的验证表明局部纹理模式(LTP)和局部衍生模式(LDP)具有更好的识别性能。 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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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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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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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
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Milton Mueller 《The Information Society》2001,17(3):151-163
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. 相似文献
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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.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
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. 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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Leah A. Lievrouw 《The Information Society》1998,14(2):83-96
The main premise of this article is that in information societies generally, and in virtual social contexts particularly, a distinctive style of interaction to facilitate the communication of difference, heterotopic communication , has emerged. It rests on two cultural foundations: an ideological belief in the positive, socially integrating power of communication, and a prevailing ethic of instrumental rationality, subjective individualism, and strategically practiced self-interest. The former is demonstrated by the use of simulation and spectacle as sources of information; exhibitionism/voyeurism as a communicative style; and the awareness of surveillance. The latter is seen in the competitive use of knowledge as a commodity; a surface globalism masking deep parochialism; lateral as well as vertical information inequity; and the use of public versus private as strategies for engagement rather than as spaces. Those who engage in heterotopic communication resort to their 'own devices' both in the sense of personal agendas, strategies, interests, and interpretations, and in the form of the telecommunication tools that help realize them. These personal and technological devices allow individuals with the right educational and technical resources to avoid exposure to disagreement, difference, or other information that does not serve their direct purposes or reflect their particular views of the world; yet they also help convey the appearance of openness, availability, and cooperation. This style of interaction is used strategically in combination with information and communication technologies to gain social or economic advantages, but it may encourage social separatism and parochialism, inhibit the negotiation of disputes, and emphasize competing interests. 相似文献