无源RFID标签用材料研究进展

射频识别(RFID)是一种非接触式的自动识别技术,它是物联网的核心技术。该技术通过射频信号自动识别目标对象并获取相关信息数据,该识别工作不需要人工干预,RFID标签可在各种恶劣环境中工作。RFID的应用非常广泛,尤其是在服装、资产管理等方面的应用最为成熟。RFID标签是RFID技术中必不可少的重要组成部分。随着新材料、新工艺的出现与发展,RFID标签的新产品不断地涌现出来,就近年出现的一些与新材料密切相关的RFID标签新产品与新制造工艺、方法进行了总结。新材料的发展与新工艺的出现为物联网核心技术RFID标签产业提供了新的技术方向和新的经济增长点。     

Utilizing the multiple facets of WWW contents

Current query languages for the Web (e.g., W3QL, WebLog and WebSQL) explore the structure of the Web. However, usually, the structure of the Web has little to do with the semantics of the data. Therefore, it is practically difficult to pose database queries over the Web. We introduce a new type of tags for denoting the semantics of data stored in HTML pages. These semantic tags (implemented as HTML comments) superimpose on HTML pages semistructured objects in the style of the OEM model. The paper discusses two implemented tools for fully utilizing the semantics. The first is a visualization tool for displaying both the HTML reading of Web pages and the OEM reading of Web pages. The second tool is a query language, similar to LOREL, that can query the HTML structure and/or the OEM reading. The above formalism and tools provide data-modeling capabilities for the Web that fit its heterogeneous nature. Real database queries, taking the OEM point of view, can be formulated, including queries about the schema as well as queries about the HTML structure of Web pages. Therefore, the query language is not restricted to portions of the Web in which semantic tags are used.     

Analysis of Expressed Sequence Tags from Chinese Bayberry Fruit (Myrica rubra Sieb. and Zucc.) at Different Ripening Stages and Their Association with Fruit Quality Development

A total of 2000 EST sequences were produced from cDNA libraries generated from Chinese bayberry fruit (Myrica rubra Sieb. and Zucc. cv. “Biqi”) at four different ripening stages. After cluster and assembly analysis of the datasets by UniProt, 395 unigenes were identified, and their presumed functions were assigned to 14 putative cellular roles. Furthermore, a sequence BLAST was done for the top ten highly expressed genes in the ESTs, and genes associated with disease/defense and anthocyanin accumulation were analyzed. Gene-encoding elements associated with ethylene biosynthesis and signal transductions, in addition to other senescence-regulating proteins, as well as those associated with quality formation during fruit ripening, were also identified. Their possible roles were subsequently discussed.     

RFID电子标签在家电产品检测系统中的应用

本文介绍RFID电子标签技术在家用电器产品生产检测系统中的应用,通过电子标签技术实现测试装置及被测家电产品在环形检测线上的定位和绑定,从而使上位计算机能够对每台家电产品的运行特性数据进行采集,提高检测系统可靠性。     

Evaluation of an innovative system for improving readability of passive UHF RFID tags attached to reusable plastic containers

Radio frequency identification (RFID) is a contactless identification technology that has proven to work well in conjunction with reusable plastic containers (RPCs). The impact of this technology on returnable containers has been explored by several past studies. This study evaluates an innovative system for improving readability of passive UHF RFID tags in conjunction with RPCs. The system involves an energy transfer device (ETD), which when attached to the RPCs, passively transfers radio frequency signals to interior regions of a unitized load thereby improving the readability of all RFID tags attached to the RPCs. This study included an evaluation of the improvement in readability of tagged RPCs in a unitized load with forklift truck speed, product type and pallet pattern as the variables and with readability as the main control variable. It was observed that ETDs vastly improve the readability rates by nearly 97%. Results are also included in this paper describing the effects of the product type, pallet patterns and forklift truck speeds on the readability of tagged RPCs in a unitized load. Copyright © 2011 John Wiley & Sons, Ltd.     

Fluorescent tags to visualize defects in Al2O3 thin films grown using atomic layer deposition

Defects and cracks in thin film barriers that are coated on polymers allow the leakage of reactive species through the polymer substrate. Fluorescent tags have been developed to visualize defects and cracks in thin film barriers and to inspect rapidly the barrier quality with minimal sample preparation. For Al₂O₃ films with a thickness of 25 nm deposited on polyethylene naphthalate polymer substrates using atomic layer deposition techniques, the fluorescent tags have identified cracks ~ 20 nm in width after applied strain and have observed individual defects as small as ~ 200 nm in diameter.     

面向EPC Gen2标准的RFID标签分组多位隙并行识别协议

在分析EPCglobal UHF class1 generation2和基于DFSA协议的高速标签识别算法的基础上,采用位隙FSA协议标签响应标志位隙的设置方法,通过在标签上设置一个组位隙响应标志字,提出了一种EPC Gen2 标准下的RFID标签分组多位隙并行识别协议GMBPIP,设计了一条新的分组查询命令和基于DFSA的多组标签并行识别协议流程,从理论上了分析GMBPIP协议的性能,并使用EPC Gen2 标准协议时间参数进行了仿真实验。结果表明,GMBPIP协议在不增加标签太多计算负担的情况下,能够在EPC Gen2标准下有效降低时隙空闲率和冲突率,提高了标签的识别率、时隙利用率;平均识别率不仅突破了帧时隙ALOHA协议最高36.8%的瓶颈,而且高于目前文献所述同类算法的性能指标,达到了70.95%~81.61%。GMBPIP可以作为低成本RFID系统高速识别大量被动标签的支撑协议。     

不定长RFID标签反碰撞识别算法

射频识别技术中存在标签冲突问题,通常采用定长标签的反碰撞识别方法来解决。针对不定长标签的反碰撞识别,设计一种对RFID标签进行识别的高效二进制树形反碰撞算法——U-算法。模拟实现的测试与分析结果表明,U-算法具有二进制树形算法的优点,能达到41.67%的系统识别效率。     

基于多叉树的RFID克隆攻击快速检测

为了提高克隆标签检测的准确度和效率,提出了一个基于多叉树的RFID克隆攻击检测方法(MT-CAI).MT-CAI用一个多叉树防碰撞算法来发现不可调解的碰撞,可以高效地发现所有的克隆标签.从性能分析和仿真实验可以看到,MT-CAI不仅能够检测出所有克隆标签,而且其执行时间远小于GREAT的执行时间.MT-CAI方法在检测时间和检测的准确度方面都优于现有的克隆标签检测协议.     

基于简介和评论的标签推荐方法研究

Web 2.0时代,社会标签是信息资源组织的一种重要方式。标签推荐能够有效的帮助用户收集、定位、查找和共享在线资源。以往的标签推荐算法只是基于一种文本信息,比如基于电影的简介文本来进行标签推荐。但是实际上电影往往存在多种文本信息,比如同时存在摘要信息和评论信息,不同类型的信息能够反映电影的不同方面的属性,因此为了提高电影标签推荐的准确率和有效性,我们同时根据电影的简介和短评进行电影标签自动推荐,并使用多种方法融合基于不同类型文本的标签推荐的结果,实验证明,使用不同类型信息进行标签推荐能够比单一使用一种文本信息进行标签推荐有很大的提升。