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T_(0)空间的ω^(*)-well-filtered反射
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作者 蔺立群 《江西科学》 2025年第2期309-312,共4页
证明T_(0)空间范畴的子范畴是它的反射子范畴是拓扑学和范畴论中的一个重要内容。引入RDω^(*)基与RD_(ω*)^(*)基的概念并借助于RD_(ω*)^(*)基构造了一个T_(0)空间的反射。
关键词 RDω*基 RD_(ω*)^(*)基 ω^(*)-well-filtered空间 反射
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A&zeta;x- and Open <i>C<sub>D</sub><sup>*</sup></i>-Filters Process of Compactifications and Any Hausdorff Compactification
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作者 Hueytzen J. Wu Wan-Hong Wu 《Advances in Pure Mathematics》 2012年第4期296-300,共5页
By means of a characterization of compact spaces in terms of open CD*-filters induced by a , a - and open CD*-filters process of compactifications of an arbitrary topological space Y is obtained in Sec. 3 by embedding... By means of a characterization of compact spaces in terms of open CD*-filters induced by a , a - and open CD*-filters process of compactifications of an arbitrary topological space Y is obtained in Sec. 3 by embedding Y as a dense subspace of , YS = {ε |ε is an open CD*-filter that does not converge in Y}, YT = {A|A is a basic open CD*-filter that does not converge in Y}, is the topology induced by the base B = {U*|U is open in Y, U ≠φ} and U* = {F∈Ysw (or YTw)|U∈F}. Furthermore, an arbitrary Hausdorff compactification (Z, h) of a Tychonoff space X?can be obtained from a by the?similar process in Sec.3. 展开更多
关键词 Net OPEN FILTER OPEN CD*-filter Base Basic OPEN CD*-filter OPEN CD*-filter -filter x-filter Tychonoff Space Normal T1-Space Compact Space COMPACTIFICATIONS Stone-Cech COMPACTIFICATION Wallman COMPACTIFICATION
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基于Netfilter框架的L7-filter模块实现研究与应用 被引量:1
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作者 张辉 李剑 刘金刚 《信息网络安全》 2011年第4期78-80,100,共4页
本文介绍了Netfilter框架的工作原理和Netfilter扩展匹配模块的实现机制。L7-filter是防火墙体系Netfilter的一个扩展匹配模块,其功能是利用正则表达式匹配技术基于数据流的应用层内容的过滤。本文分析了L7-filter的原理和实现,并举例... 本文介绍了Netfilter框架的工作原理和Netfilter扩展匹配模块的实现机制。L7-filter是防火墙体系Netfilter的一个扩展匹配模块,其功能是利用正则表达式匹配技术基于数据流的应用层内容的过滤。本文分析了L7-filter的原理和实现,并举例说明了如何使用L7-filter匹配各种协议。 展开更多
关键词 NETFILTER 扩展匹配模块 L7-filter 正则表达式匹配
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非结构化P2P网络中基于物理位置与Bloom-filter的副本一致性维护机制 被引量:1
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作者 郭良敏 杨寿保 +2 位作者 王淑玲 张瑞 牛宪龙 《电子与信息学报》 EI CSCD 北大核心 2011年第4期1012-1016,共5页
拥有一个有效的一致性维护机制是保证P2P系统正常运行的关键之一。非结构化P2P系统中的消息传播主要通过邻居的转发,会产生大量冗余消息;并且,系统中节点的物理位置和逻辑位置存在着不匹配,会增加消息传播的时间开销。为减少一致性维护... 拥有一个有效的一致性维护机制是保证P2P系统正常运行的关键之一。非结构化P2P系统中的消息传播主要通过邻居的转发,会产生大量冗余消息;并且,系统中节点的物理位置和逻辑位置存在着不匹配,会增加消息传播的时间开销。为减少一致性维护代价,该文提出基于物理位置与Bloom-filter的副本一致性维护机制。该机制利用复杂网络中社团划分思想,将网络中的节点按物理位置划分成多个簇,簇中节点物理位置相近,让更新在簇内进行;再引入双层Bloom-filter和冗余二级邻居改进现有更新消息的传播方法。实验表明,该机制可以降低更新消息的冗余传播和一致性维护的时间开销。 展开更多
关键词 副本一致性 物理位置 Bloom-filter 冗余二级邻居
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约束Minimax问题的SQP-Filter算法及收敛性 被引量:2
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作者 谢亚君 马昌凤 《西华大学学报(自然科学版)》 CAS 2011年第6期61-64,共4页
提出了一个求解带等式和不等式约束的Minimax问题的SQP-Filter算法,每步通过求解2个二次规划子问题来得到搜索方向,并沿该方向做线搜索。该算法避免了较难的罚因子的选取,克服了Maratos效应,并在适当的假设条件下,得到了算法的全局收敛性。
关键词 运筹学 MINIMAX问题 SQP-filter算法 全局收敛性
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Prime MP-filter Spaces of Fuzzy Implication Algebras 被引量:8
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作者 LIU Chun-hui XU Luo-shan 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第2期246-253,共8页
In this paper,the topological space(PF_(MP)(X),T) based on prime MP-filters of a lattice FI-algebra X is constructed firstly and we proved that it is a compact T_0-space if X with condition(P).Secondly,we restricted T... In this paper,the topological space(PF_(MP)(X),T) based on prime MP-filters of a lattice FI-algebra X is constructed firstly and we proved that it is a compact T_0-space if X with condition(P).Secondly,we restricted T to the set of all maximal MP-filters MF_(MP)(X) of X and concluded that(PF_(MP)(X),T |_(PF_(MP)(X)) )is a compact T_2 space if X with conditions(P) and(S). 展开更多
关键词 Fuzzy implication algebra MP-filter prime MP-filter topological space
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基于Guide-filter的中国书法作品中印章信息的提取 被引量:2
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作者 许鹏飞 《传感器与微系统》 CSCD 2016年第12期125-128,共4页
针对中国书法作品中存在的印章信息难以准确提取的问题,提出基于Guide-filter的中国书法作品中印章信息的提取算法。算法充分利用Guide-filter具有较好保持图像边缘信息的能力,以及最大限度逼近目标信息的特性,以双阈值法得到的二值图... 针对中国书法作品中存在的印章信息难以准确提取的问题,提出基于Guide-filter的中国书法作品中印章信息的提取算法。算法充分利用Guide-filter具有较好保持图像边缘信息的能力,以及最大限度逼近目标信息的特性,以双阈值法得到的二值图像之间的残差图像作为Guide-filter的输入图像,以原始图像作为Guide-filter的引导图像,最终获得较为准确的印章信息。此外,利用边缘密度的概念,通过计算提取印章区域的边缘密度来对印章提取效果进行客观性评价。实验表明:提出算法能够较好地提取出中国书法作品中的印章信息。 展开更多
关键词 中国书法作品 印章 Guide-filter 边缘密度
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Netfilter防火墙下L7-filter模块的研究和应用 被引量:2
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作者 曾树洪 《微计算机信息》 2010年第9期90-92,共3页
分析了Netfilter防火墙的工作原理和L7-filter的工作原理,介绍了添加layer7模块的方法,举例说明了如何使用L7-fil-ter过滤MSN、QQ等数据包和Flash等文件格式的数据包。分析L7-filter模板文件的格式,并给出了编写L7-filter模板文件的方... 分析了Netfilter防火墙的工作原理和L7-filter的工作原理,介绍了添加layer7模块的方法,举例说明了如何使用L7-fil-ter过滤MSN、QQ等数据包和Flash等文件格式的数据包。分析L7-filter模板文件的格式,并给出了编写L7-filter模板文件的方法。利用该方法可以更加灵活的配置适合不同需要的防火墙。 展开更多
关键词 防火墙 Iptales LINUX L7-filter
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e-FILTERS OF MS-ALGEBRAS
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作者 M. Sambasiva RAO 《Acta Mathematica Scientia》 SCIE CSCD 2013年第3期738-746,共9页
The notion of e-filters is introduced in an MS-algebra and characterized. The concept of D-filters is introduced and a set of equivalent conditions under which every D-filter is an e-filter are given. The properties o... The notion of e-filters is introduced in an MS-algebra and characterized. The concept of D-filters is introduced and a set of equivalent conditions under which every D-filter is an e-filter are given. The properties of the space of all prime e-filters of an MS-algebra are observed. The concept of D-prime filters is introduced and then a set of equivalent conditions axe derived for a prime e-filter to become a D-prime filter in topological terms. 展开更多
关键词 MS-ALGEBRA e-filter dense element D-filter D-prime filter minimal prime filter Hausdorff space
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Spectral properties and geometric interpretation of R-filters
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作者 冷拓 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第1期109-120,共12页
By applying the Fourier analysis, we study the spectral properties of R- filters. Further, we prove that R-filters are a generalization of least squares polynomial adjustment, and we give the geometric interpretation ... By applying the Fourier analysis, we study the spectral properties of R- filters. Further, we prove that R-filters are a generalization of least squares polynomial adjustment, and we give the geometric interpretation of R-filters. 展开更多
关键词 R-filter HP-filter spectral properties Fourier analysis Hess-matrix operator theory
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Hardware Architecture Design of Block-Matching and 3D-Filtering Denoising Algorithm
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作者 张昊 刘文江 +2 位作者 王若琳 刘涛 戎蒙恬 《Journal of Shanghai Jiaotong university(Science)》 EI 2016年第2期173-183,共11页
Block-matching and 3D-filtering(BM3D) is a state of the art denoising algorithm for image/video,which takes full advantages of the spatial correlation and the temporal correlation of the video. The algorithm performan... Block-matching and 3D-filtering(BM3D) is a state of the art denoising algorithm for image/video,which takes full advantages of the spatial correlation and the temporal correlation of the video. The algorithm performance comes at the price of more similar blocks finding and filtering which bring high computation and memory access. Area, memory bandwidth and computation are the major bottlenecks to design a feasible architecture because of large frame size and search range. In this paper, we introduce a novel structure to increase data reuse rate and reduce the internal static-random-access-memory(SRAM) memory. Our target is to design a phase alternating line(PAL) or real-time processing chip of BM3 D. We propose an application specific integrated circuit(ASIC) architecture of BM3 D for a 720 × 576 BT656 PAL format. The feature of the chip is with 100 MHz system frequency and a 166-MHz 32-bit double data rate(DDR). When noise is σ = 25, we successfully realize real-time denoising and achieve about 10 d B peak signal to noise ratio(PSNR) advance just by one iteration of the BM3 D algorithm. 展开更多
关键词 block-matching and 3D-filtering(BM3D) denoising algorithm IMPLEMENTATION BLOCK-MATCHING 3D-filtering AGGREGATION
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基于Wash-Out-Filter方法控制非线性系统Hopf分岔 被引量:6
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作者 安春 张庆灵 +1 位作者 张艳 苏湛 《东北大学学报(自然科学版)》 EI CAS CSCD 北大核心 2008年第10期1381-1384,共4页
Hopf分岔往往导致系统的周期性振荡直至失稳,为此,基于wash-out-filter方法为非线性系统设计Hopf分岔状态反馈控制器.在保持平衡点不变的情况下,使得系统在期望的参数值处,将原来发生的亚临界Hopf分岔转化为超临界Hopf分岔,并保证系统... Hopf分岔往往导致系统的周期性振荡直至失稳,为此,基于wash-out-filter方法为非线性系统设计Hopf分岔状态反馈控制器.在保持平衡点不变的情况下,使得系统在期望的参数值处,将原来发生的亚临界Hopf分岔转化为超临界Hopf分岔,并保证系统在参数值范围内是渐近稳定的.分别以一维和二维非线性系统为例,仿真结果验证了所提方法的正确性和有效性. 展开更多
关键词 wash-out-filter HOPF分岔 非线性系统 状态反馈控制 渐近稳定
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A Comparison of Higher-Order Active Band-Pass R-Filter Response with Equivalent Band-Pass RC-Filter Response at Varying Q-Factors
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作者 Alexander Nwabueze Amah Iorkyaa Ahemen Bernard Atsuwe 《Circuits and Systems》 2014年第10期229-237,共9页
In this paper a comparison of a sixth-order active band pass R-filter output response with the output response of a sixth-order band pass RC-filter at different quality factors (Q = 2, 5, 7, 8 and 10) was carried out ... In this paper a comparison of a sixth-order active band pass R-filter output response with the output response of a sixth-order band pass RC-filter at different quality factors (Q = 2, 5, 7, 8 and 10) was carried out at a fixed frequency of 10 KHz. The architecture used in the design is the multiple feedbacks for both filter networks. The simulated response characteristics show that both filters (R- and RC-filters) have their mid-band gains increasing with Q, while their bandwidths monotonically decreased with Q-values. The bandwidths are in the range of 22.23 dB to 62.97 dB and –55.49 dB to –50.81 dB (Q = 2 to 10) for R- and RC-filters respectively. At higher Q-values, R-filter showed better selectivity with a smaller bandwidth (400 Hz) at the edge of the pass band, when compared to 450 Hz for the RC-filter. The roll-off rate around –58.9 dB/decade for the R-filter appears to be that of a third-order filter response, while the RC-filter has its response in the range –106 to –132 dB/decade which is in the neighbourhood of an ideal sixth-order response (roll-off of 120 db/decade). A shift in the center frequency with Q was observed for the RC-filter only. 展开更多
关键词 R-filter RC-filter Gain Roll-Off Multiple Feedback Sixth-Order FILTER
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New Insights in the Biodegradability and the Ecotoxicological Effects of Solar Products Containing Mineral and Chemical UV-Filters on Marine Zoo- and Phytoplanktons: An in silico and in vitro Study
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作者 Jean-Claude Hubaud Karim Mekideche +1 位作者 Jean-Eric Branka Luc Lefeuvre 《Journal of Cosmetics, Dermatological Sciences and Applications》 2024年第1期98-111,共14页
Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our ... Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our work in 2019 concerning the ecotoxicological effects of such formulations on corals (Seriatopora hystrix), we here provide some new information about the biodegradability and the ecotoxicological effects of these products on marine zoo- and phytoplankton. Therefore, we choose to realize in silico and in vitro studies of the biodegradability of several solar products but also to evaluate the ecotoxicological effects of these products on one phytoplankton, i.e. Phaeodactylum tricornutum, and one zooplankton, i.e. Acartia tonsa, of a great importance for sea species survival (notably as sources of food). Materials and methods: Two different approaches were used to study the biodegradability of the tested products: One in silico method and an in vitro one. 2 solar products were involved in the in silico study which consisted in the determination of the degradation factor (DF) of each ingredient of the tested formulas in order to finally obtain their estimated biodegradability percentage. Already available data concerning each ingredient coupled to a computer model developed with one of our partners were used to achieve this study. The in vitro study involved 8 formulas containing UV-filters and was led by following the OECD 301 F guidelines. Ecotoxicological studies of 7 of the formulas containing UV-filters were for their part realized by following the ISO 10253 guidelines for the experiments led with Phaeodactylum tricornutum, and the ISO 14669 guidelines for the experiments led with Acartia tonsa. In these studies, the effect of each tested product on crustaceans’ mortality and algal growth inhibition was assessed. Results: The in silico study predicted that formulas containing chemical UV-filters display a high biodegradability (superior to the threshold value of 60% given by the OECD 301 F guidelines). In the in vitro part of our work, the 8 tested formulas showed a biodegradability slightly inferior to the one predicted in the in silico experiments. Therefore, in order to evaluate if these calculated biodegradability value could have significant harmful effects on zoo- or phytoplankton, we studied the effect of our products regarding the growth inhibition on Phaeodactylum tricornutum and the mortality on Acartia tonsa. In this last part of the study, all the tested products were classified as “non ecotoxic” following an internal classification based on Part 4 entitled “Environmental Hazards” of Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 9<sup>th</sup> edition (2021). Conclusions: These results are notably in line with those published by our teams in 2019 on the effects of solar cosmetic products on corals and seem to confirm that formulas containing mineral and chemical UV-filters can be daily used without displaying significant noxious effects on marine fauna and flora. . 展开更多
关键词 UV-filters Chemical UV-filter BIODEGRADABILITY ECOTOXICOLOGY in silico in vitro Zooplankton Phytoplankton Phaeodactylum tricornutum Acartia tonsa
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基于Washout-filter方法的电力系统动分岔控制 被引量:9
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作者 马幼捷 李小双 +3 位作者 周雪松 李季 问虎龙 贾丽英 《电力系统保护与控制》 EI CSCD 北大核心 2011年第23期54-59,共6页
电力系统中的分岔现象严重影响系统的稳定性和电压质量,为提高系统的稳定性和电能质量,对分岔现象的控制迫在眉睫。介绍了动分岔的相关理论和目前非线性系统中常用的两种分岔控制方法。重点论述了用Washout-filter法对电力系统的动分岔... 电力系统中的分岔现象严重影响系统的稳定性和电压质量,为提高系统的稳定性和电能质量,对分岔现象的控制迫在眉睫。介绍了动分岔的相关理论和目前非线性系统中常用的两种分岔控制方法。重点论述了用Washout-filter法对电力系统的动分岔进行控制。研究表明:对系统进行动分岔控制后,施加控制前系统存在的两个动分岔点消失,并且很大程度上增加了系统的稳定运行域。理论分析和仿真结果相符,证实了该控制方法的有效性。 展开更多
关键词 电力系统 动分岔 HOPF分岔 高通滤波器控制 稳定域 负荷裕度
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X-filter新型绿液处理设备 被引量:3
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作者 张保元 《中华纸业》 CAS 北大核心 2010年第20期75-78,共4页
主要介绍了新型绿液处理设备的结构、功能,与传统的绿液澄清器相比更为环保、节能,生产能力大,占地面积小,自动化程度高,工人劳动强度小,工作环境清洁,设备维护简单,适合于大型碱回收的配套设备。处理后的绿液浊度低,便于后续的洗涤过滤。
关键词 X-filter绿液处理设备 结构 技术参数 顺控 过滤 浓缩 压力平衡 放空 滤网洗涤 酸洗
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基于多核处理器的L7-Filter规则匹配改进算法
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作者 余涛 吴卫东 《计算机应用》 CSCD 北大核心 2012年第3期609-613,共5页
针对多核处理器的体系结构和网络数据流在时间上的局部性特点,提出了一种基于多核处理器的分链动态适应算法。该算法通过对网络数据流进行类型分类并根据网络数据流的时间局部性对规则链进行动态优化,从而有效减少了多核处理器下L7-Fil... 针对多核处理器的体系结构和网络数据流在时间上的局部性特点,提出了一种基于多核处理器的分链动态适应算法。该算法通过对网络数据流进行类型分类并根据网络数据流的时间局部性对规则链进行动态优化,从而有效减少了多核处理器下L7-Filter对网络数据流的匹配次数,显著提升了规则匹配效率。仿真实验结果表明:在网络数据包个数相同条件下,所提算法在性能上约有7%的提高。随着网络数据包个数的增加,性能优越性更加明显。 展开更多
关键词 多核处理器 网络数据流 L7-filter 时间局部性 数据包分类 动态优化
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可数-定向集与ω^(*)-well-filtered空间 被引量:1
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作者 张曼怡 徐晓泉 《模糊系统与数学》 北大核心 2023年第6期90-99,共10页
本文利用可数-定向集,引入了ω^(*)-Rudin空间和ω^(*)-well-filtered决定空间的概念,讨论了ω^(*)-well-filtered空间及相关空间的收缩性、乘积性、反射性等基本性质,给出了ω^(*)-well-filtered性的等价刻画,得到了如下主要结果:(1)ω... 本文利用可数-定向集,引入了ω^(*)-Rudin空间和ω^(*)-well-filtered决定空间的概念,讨论了ω^(*)-well-filtered空间及相关空间的收缩性、乘积性、反射性等基本性质,给出了ω^(*)-well-filtered性的等价刻画,得到了如下主要结果:(1)ω^(*)-Rudin空间的连续收缩核仍然是ω^(*)-Rudin空间;(2)ω^(*)-well-filtered决定空间的连续收缩核仍然是ω^(*)-well-filtered决定空间;(3)设{X_(i):1≤i≤n}是有限个T_(0)空间,则n∏i=1X_(i)是ω^(*)-well-filtered决定空间当且仅当每个因子空间X_(i)是ω^(*)-well-filtered决定空间(i=1,2,…,n);(4)ω^(*)-well-filtered空间的连续收缩核是ω^(*)-well-filtered空间;(5)设{X_(i):i∈I}是一族T_(0)空间,则∏i∈IX_(i)是ω^(*)-well-filtered空间当且仅当每个因子空间X_(i)是ω^(*)-well-filtered空间(i∈I);(6)ω^(*)-well-filtered空间范畴是T_(0)空间范畴的满子反射范畴,并给出了T_(0)空间ω^(*)-well-filtered反射的具体构造。 展开更多
关键词 可数-定向集 ω^(*)-well-filtered空间 ω^(*)-d-空间 Smyth幂空间 反射
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RedHat As 5下L7-filter封包过滤的搭建应用 被引量:5
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作者 李剑 罗洪梅 《计算机应用》 CSCD 北大核心 2009年第B06期114-115,121,共3页
分析了Linux netfilter/iptables架构下L7-filter的功能、工作原理和实现机制,利用iptables的独立模块L7-fiter实现了具有封锁MSN、QQ等P2P封包过滤功能,并进行相关测试。测试结果表明,该layer7的封包过滤可以在具有网络地址转换(NAT)... 分析了Linux netfilter/iptables架构下L7-filter的功能、工作原理和实现机制,利用iptables的独立模块L7-fiter实现了具有封锁MSN、QQ等P2P封包过滤功能,并进行相关测试。测试结果表明,该layer7的封包过滤可以在具有网络地址转换(NAT)功能的防火墙体系上实现,限制对P2P等大流量数据对网络带宽的占用,使得网络运行更加高效稳定。 展开更多
关键词 内核 七层过滤 IPTABLES 网络地址转换 P2P
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Study on mode-filtered light sensor for methane detection 被引量:4
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作者 Suo Zhu Wu Shao Min Shuang +4 位作者 Yan Zhang Zhong Ping Li Martin M.E Choi Cai Hong Zhang Chuan Dong 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第2期210-212,共3页
A novel mode-filtered light gas sensor has been reported. It was constructed by inserting an optical fiber deposited by a thin silicone cladding of cryptophane A into a fused-silica capillary. When different concentra... A novel mode-filtered light gas sensor has been reported. It was constructed by inserting an optical fiber deposited by a thin silicone cladding of cryptophane A into a fused-silica capillary. When different concentration of methane gas was introduced to the sensor, the phenomenon that mode-filtered light intensity decreased with the increasing concentration of methane was observed. And a linear relationship was obtained within the methane concentration range of 0.0-16.0% (v/v). The detection limit was 0.06% (v/v). The mode-filtered light sensor has been exploited to respond to various concentrations of methane gas at room temperature. 展开更多
关键词 Mode-filtered light METHANE Cryptophane A
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