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指纹是人体的一项生物特征,是指手指末端正面皮肤上凸凹不平产生的纹路。尽管指纹只是人体皮肤的一小部分,但是,它蕴涵大量的信息,每个人指纹的纹路在图案、断点和交叉点上是各不相同的。随着计算机技术的发展,大容量存储器和处理芯片的存在,使得指纹识别技术的可靠性得到较大提高,成本得到很大降低,这项技术的安全系数也较普通系统有了很大的提高。指纹IC卡,让你生活更便捷目前,我国在金融、电子商务中使用的基本上是智能IC卡,这类卡在 相似文献
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随着信息技术的迅猛发展,新技术不断在图书馆中得到应用,图书馆业务管理和服务手段也与时俱进,呈现出智能化、现代化特点。近几年来,智能卡在全国各地域、各行业得到了广泛的应用和推广。图书馆作为服务机构,在经历了传统的读者证、读者卡时代之后,也逐步在向智能卡这个方向推进。图书馆智能卡的使用可以实现馆内的借书。实现馆内费用的结算和管理,读者进入馆内借阅的身份验证。 相似文献
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本文介绍了一种计算机用IEEE-488接口卡的硬件和软件设计。硬件主要采用一块8255芯片,软件使用C语言。该接口实现了与数字万用表的连接,可以与任何具有IEEE-488接口的仪器相连接。 相似文献
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Journal status 总被引:4,自引:1,他引:4
Summary The status of an actor
in a social context is commonly defined in terms of two factors: the total
number of endorsements the actor receives from other actors and the prestige of
the endorsing actors. These two factors indicate the distinction between popularity
and expert appreciation of the actor, respectively. We refer to the former as
popularity and to the latter as prestige. These notions of popularity and
prestige also apply to the domain of scholarly assessment. The ISI Impact
Factor (ISI IF) is defined as the mean number of citations a journal receives
over a 2 year period. By merely counting the amount of citations and
disregarding the prestige of the citing journals, the ISI IF is a metric of
popularity, not of prestige. We demonstrate how a weighted version of the
popular PageRank algorithm can be used to obtain a metric that reflects
prestige. We contrast the rankings of journals according to their ISI IF and
their Weighted PageRank, and we provide an analysis that reveals both
significant overlaps and differences. Furthermore, we introduce the Y-factor
which is a simple combination of both the ISI IF and the weighted PageRank, and
find that the resulting journal rankings correspond well to a general
understanding of journal status. 相似文献
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Pop-up cards are an interesting form of paper art with intriguing geometrical properties. Normally, there are two types of pop-up cards. Origami architecture is a 90-degree card and a v-fold pop up is a 180-degree card. Recently, some approaches have been proposed to aid in the design of a pop-up card. Most of the works on pop-up crafting have used a software tool to design pop-up cards. However, a design tool for a 90-degree card cannot be adopted for the design of a 180-degree card. For the same reason, a method for producing a 180-degree card also cannot be applied to a 90-degree card. This paper proposes a directed acyclic graph (DAG) for designing both types of pop-up cards. These two types of pop-up cards could be created with DAG data structure. The DAG algorithm ensures that the pop-up card is foldable, stable, and intersection-free when opened and closed. The proposed method is demonstrated with various paper pop-up cards, and experimental examples are presented. 相似文献
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CF卡在单片机系统中的应用 总被引:3,自引:0,他引:3
Compact Flash Card卡是近年来发展迅速的一种非易失性存储器,其内部集成了微控制器、Flash Memory阵列和读写缓冲区,具有体积小、存储容量大、数据保存具有非易失性、接口标准统一、便于携带等优点。文章介绍了Compact Flash Card的结构、工作方式和磁盘文件管理系统及在Compact Flash Card上的应用。并给出了Compact FlashCard与单片机的接口电路和单片机读写Compact Flash Card的汇编语言源程序。 相似文献
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Virtual spectrum analyzer based on data acquisition card 总被引:9,自引:0,他引:9
A virtual spectrum analyzer based on a data acquisition card is presented. The implemented functions are described. The properties of the device were examined. Such features as accuracy and speed are considered. The virtual analyzer and an instrument equipped with a DSP are compared. The integrated programming package LabView was used to design the analyzer 相似文献
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采用传统的高温固相反应法制备了钙钛矿氧化物Eu1-xCaxMnO3(x=0,0.1,0.2,0.3,0.4,0.5)多晶体系样品。通过样品的XRD谱线、磁化强度随温度、外加磁场的变化曲线(M-T、M-H)等数据研究了Ca不同掺杂量对钙钛矿氧化物EuMnO3系列多晶样品的居里温度、磁熵变、磁相变等的影响。结果表明,Eu1-xCaxMnO3(x=0,0.1,0.2,0.3,0.4,0.5)系列陶瓷样品呈现良好的单相性,空间点群为Pnma。低浓度掺杂的样品存在一个TC,高浓度掺杂的样品出现两个磁转变点,且由于双交换相互作用,随着Ca的掺杂,TC逐渐增大,当掺杂量达到0.4时,低温下的TC却明显减小。根据-ΔSM和RCP值可知,Eu0.7Ca0.3MnO3是该组样品中比较适合做磁制冷的材料。通过对Loop曲线的分析可知该组样品经历了由一级相变向二级相变转变的过程。 相似文献