一种改进的神经网络算法车牌识别算法研究

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.     

粒子群算法优化BP神经网络的指纹识别技术

指纹识别技术是当今应用最广泛的生物识别技术之一。在指纹识别过程中,图像处理、特征提取、匹配等过程数据量庞大,计算比较烦琐。BP神经网络具有良好的自学习能力、强大的分类能力和容错能力,将其应用到指纹识别中是可行的。为改进BP神经网络计算速度较慢,梯度下降法不能处理一些不可微传递函数的问题,采用粒子群算法对BP算法进行优化,提高了指纹识别的速度和准确度。     

基于计算机视觉的电器漏电智能识别方法研究

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。     

随机比较Gabor滤波的可撤销掌纹识别算法

针对掌纹生物特征识别的模板安全保护,本文研究并提出一种Gabor滤波与混沌矩阵进行随机比较的可撤销掌纹识别方法。首先使用Gabor滤波器与经过预处理的掌纹图像卷积;然后将滤波得到的模板与混沌矩阵进行随机比较,得到可撤销的二值模板;最后根据计算模板之间的汉明距离归类匹配。通过掌纹数据库实验表明,该算法在保护掌纹图像模板安全性的同时,提高了识别效果。     

强鲁棒性小方差类间类内特征文本数据分类

提出一种基于改进TFIDF算法的海量文本分类识别方法,将特征之间的信息熵与特征内信息熵作为文本分类识别的加权因子,采用神经网络的非线性映射能力实现权值计算和TFIDF算法的模糊化,从而解决文本分类不准确和海量文本的分类问题。采用5个类别文档,每个类别5个文档,3个特征项来进行实际试验验证,结果表明,改进的TFIDF算法能够更好的实现文本识别分类,具有更小的方差特性,对随机文本分布具有更强的鲁棒性,收敛速度更快,具有很好的应用价值。     

基于改进BP神经网络的图像识别算法

为提高图像识别的准确率和速度,结合遗传算法和BP神经网络设计了一种改进图像识别算法。由于传统BP神经网络本身存在结构参数不确定、收敛速率低、容易陷入局部最小值等问题。本文首先提取图像的颜色和纹理特征,利用BP神经网络实现特征的初步识别同时基于遗传算法在线优化BP神经网络结构参数。在此基础上,给出了图像识别流程。最后,根据证据理论实现图像识别结果融合以获得完整图像信息。仿真结果表明:所述算法具有较高的识别率和收敛速度;在少量训练样本条件下,改进BP神经网络依旧具有较好的泛化能力。     

基于神经网络的人体动态行为智能识别方法

针对传统方法的人体动态行为智能识别方法存在识别率较低等问题,提出基于神经网络的人体动态行为智能识别方法。对人体动态行为数据预处理,并构建人工神经网络模型,实现人工神经网络训练以及特征提取;将视频的光流图像放置于卷积神经网络模型中,获取图像的时域特征;融合人工神经网络特征与时域特征,并将其放入SVM中进行类别划分,实现基于神经网络的人体动态行为智能识别。仿真实验研究结果表明,所提方法能够有效提升人体动态行为识别准确率,并且整个方法的综合性能较好。     

基于不变矩和小波神经网络的交通标志识别研究

研究了用于交通标志识别的小波神经网络模型,并描述了相应的算法,给出实验结果。实验结果表明,采用不变矩提取道路交通标志的特征,再利用训练速度快、优化性能好的小波神经网络作为分类器对交通标志识别具有很好的分类能力,对实现交通标志的精度识别提供了有力的支持。与传统的BP神经网络识别方法相比,小波神经网络的训练速度更快和识别率更高,能够满足在车辆自主导航系统中对交通标志识别的要求。     

基于特征点图像匹配的面部识别方法

面部识别被认为是生物特征识别领域甚至人工智能领域最困难的研究课题之一,如何进行好面部识别工作对于生活、生产都有着十分重要的意义。本文提出一种基于特征点提取的面部识别方法,在得到已知图像和待识别图像以后,先对其进行边缘提取和点特征提取,然后基于提取的特征点进行灰度模板匹配,通过图像匹配的结果对图像进行识别。     

空中目标BP神经网络识别方法研究及应用

空中目标识别是军事信息处理中的一个重要环节,对军事目标类型的识别是一个重要的课题。通过采用基于改进BP算法的神经网络目标识别方法,对具体的军事目标类型给予识别特征描述与提取,以矩和圆度两种特征形成特征向量,将其标准化后作为BP神经网络的输入,并通过仿真对网络进行调整。仿真结果表明,此方法合理可行,对提高军事信息处理的准确性具有重要意义。     

Low doses of a red wine ingredient figh diabetes in mice

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.     

To serve and promote science development via innovation

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.     

Tracing the origin and early radiation of birds——Paleornithologist ZHOU Zhonghe

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."     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

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.     

Molecular motor assembly of a biomimetic system

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.     

Cooler temperatures inductive to locust outbreaks

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.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

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.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

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.     

The Information Environment and Universal Service

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.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

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.