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131.
该文介绍了三种测量噪声系数的方法:增益法,Y因子法和冷源法。重点介绍了当我们做精确测量时Y因子法的不足和冷源法的突破以及给出了这两种方法的实际测试例子。 相似文献
132.
《Information Security Journal: A Global Perspective》2013,22(1-3):83-93
ABSTRACTFirewalls are one of the most widely used security devices to protect a communications network. They help secure it by blocking unwanted traffic from entering or leaving the protected network. Several commercial vendors have extended their firewall capabilities to support SCADA protocols or designed SCADA-specific firewalls. Although open-source firewalls are used successfully in IT networks, their use in SCADA networks has not been properly investigated. In this research we investigate the major open-source firewalls for their use in SCADA networks and identify Linux iptables’ potential as an effective SCADA firewall. Iptables is a powerful open-source firewall solution available as part of most Linux distributions in use today. In general, use of iptables as a network-level firewall for SCADA systems has been limited to basic port and host filtering, without further inspection of control messages. We propose and demonstrate a novel methodology to use iptables as an effective firewall for SCADA systems. This is achieved by utilizing advanced iptables features that allow for dynamic inspection of packet data. It is noteworthy to mention that the proposed solution does not require any modification to the netfilter/iptables framework, making it possible to turn a Linux system into an effective SCADA firewall. The approach has been tested by defining filtering rules for the Modbus TCP protocol and validating its ability to defend against various attacks on the protocol. 相似文献
133.
辐射源具有强烈的社会敏感性,无论是丢弃还是泄漏,都会给人类社会和环境造成无法估量的损失和危害。为了使其能够进一步造福于人类社会,对辐射源进行规范使用,安全监管尤为重要。文章介绍了一套集辐射源剂量监测、RFID电子标签、GPS地球定位、位移检测、视频监控和管理为一体的安全监管物联网应用系统,以降低辐射源被盗的风险,准确高效地实现辐射源安全监管的目标。 相似文献
134.
局域网应用越来越广泛,鉴于网络宽带的有限性,提出了基于精确流量控制的局域网网关出口管理策略,网络出口管理的优化控制得以实现,有效改善了局域网络拥塞问题. 相似文献
135.
《国际互联网参考资料服务季刊》2013,18(4):21-33
Abstract This paper describes what the World Wide Web is and what is needed in order to access its information. It discusses the future of art and humanities reference resources and presents criteria for evaluating Web sites. A review of the literature related to “Generation X” and their information expectations was done. There is an annotated list of specific World Wide Web resources related to African Diaspora, American Poetry, Comparative Literature, Gay and Lesbian Literature, and Outsider Art. This list provides examples for evaluation and is not meant to be exhaustive. 相似文献
136.
《国际互联网参考资料服务季刊》2013,18(1-2):89-98
SUMMARY As dynamic content is filling the Internet, so are choices for implementing this service/tool for Web developers. This article concentrates on one of the solutions that offers choices and tools in a single free package. Zope delivers Web-based content using a variety of sources and Internet connections. At Appalachian State University, Ask A Librarian http://www.library.appstate.edu/reference/askref.html concentrates on using Zope, the PostgreSQL database, e-mail, and the Web to offer patrons the opportunity to receive guidance from reference librarians while at a remote location. 相似文献
137.
Alexander Savelyev 《Information & Communications Technology Law》2013,22(1):27-44
The emergence of so-called free or open-source software and the growth of its economic importance in various industries make questions regarding the legal status of free/open-source licenses especially important. In December 2010, new draft amendments to the Civil Code were published, introducing new concepts in order to reflect the ideas pursued by these types of licenses. This article analyzes existing problems with the legal status of free/open-source licenses, whether proposed amendments may solve them, and what risks they may create. Since Russia is among the first countries trying to include provisions on free/open-source licenses in its legislation, such analysis may be of interest to foreign lawmakers since the concept of open source is universal all over the world. 相似文献
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分析2010年长江流域暴雨洪水,有利于更全面认识长江流域暴雨洪水特性,可为今后更好开展长江流域防汛水情保障工程。从主汛期长江流域暴雨及气候特征、干支流主要洪水过程及洪水特性等方面,进行了初步的总结和分析。2010年长江主汛期洪水发生范围广、持续时间长且局部地区洪水量级大,通过与三峡水库蓄水前后几次大的历史洪水分析对比,初步认为,2010年长江流域主汛期出现的洪水为长江上中游区域性较大洪水。 相似文献