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屏蔽室和半电波暗室设计施工的若干问题 总被引:1,自引:0,他引:1
介绍了屏蔽室和半电波暗室在设计和施工中需要注意的一些问题,例如:总体布局、供电照明、接地、通风、接口板、吸波材料选用、使用维护等. 相似文献
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用于电磁兼容测量的电磁屏蔽半电波暗室 总被引:1,自引:0,他引:1
叙述了EMC暗室与微波电波暗室的区别,讨论了暗室设计中需考虑的问题,最后叙述了暗室的检验方法,包括归一化地衰减和测试面场均匀性。 相似文献
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用于电磁兼容测量的电磁屏蔽半电波暗室 总被引:1,自引:0,他引:1
详细介绍了电磁屏蔽半电波暗室主要技术指标和设计要求,讨论了暗室设计中需考虑的一些实际问题和注意事项,为EMC暗室建设和验收提供依据. 相似文献
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本文简述了微波暗室静区与反射电平的基本概念,论述了空间驻波法测量暗室反射电平的基本原理和方法,重点讨论了自由空间电压驻波比法测量反射电平的数据简化处理新方法。结合我所微波暗室的测试经验,指出了微波暗室测试中应注意的问题,最后给出了我所微波暗室反射电平的实测结果。 相似文献
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该文介绍了电磁兼容测试需要的多功能电波暗室,成为多功能电波暗室应具备的基本功能,对满足标准要求的多功能电波暗室所需具备的性能指标进行描述及相应的测试要求,如基本的NSA,Svswr,FU。对在多功能电波暗室中进行不同项目测试时所对应的场地布置进行了分析,最后对多功能电波暗室的优劣进行了总结。 相似文献
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0引言:为什么要测量微波暗室的剩余互调
微波暗室分为全电波暗室和半电波暗室.全电波暗室定义为六面装有吸波材料的屏蔽室,用于模拟自由空间;半电波暗室则是五面装有吸波材料,地面为反射面,用于模拟开阔场.常见的微波暗室的墙体由铁氧体材料加微波吸波材料组成.和其他无源器件一样,微波暗室也遵循互调产生的机理.在大功率多载频的作用... 相似文献
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双喇叭微波暗室不但包含有锥形暗室和矩形暗室的特征和优点,而且建造这样的暗室能减少吸波材料和暗室建筑费用15%。柱型暗室具有独特的用途,对称性好,电磁静区的性能也比矩型暗室优良。 相似文献
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目前,软件开发的复杂性不断提高,过程模式为减少软件开发过程中的复杂性提供了一个很好的工具,为给定的任务提供了一个结构化的方法.文中首先阐明了过程、模式,以及过程模式的定义,接着描述了过程模式的3种类型:任务过程模式,步骤过程模式,阶段过程模式.过程模式是实践验证的软件开发方法,软件开发机构可用它来提高软件的质量、可维护性和可扩展性. 相似文献
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流程挖掘技术可以提取机场流程日志中的有用信息用于流程分析。但机场流程日志处于细节化的低抽象层次,不符合分析者的预期。对机场流程日志挖掘得到的流程模型呈现意面状的复杂结构,流程模型的含义难于理解。解决该问题的一种方法是通过活动挖掘,将低抽象层次活动聚类为流程模型中表征高抽象层次活动的活动类簇。为此提出了一种基于RankClus算法的活动挖掘方法,将机场流程日志的活动聚类与活动排序评分计算相结合,从而构建更易理解的活动聚类流程模型。实验结果表明,RankClus活动聚类流程模型的日志回放一致性与原生日志流程模型大致相当,但在结构复杂度上要显著低于原生日志流程模型。 相似文献
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基于在不同的天线上发送时间正交的训练序列,提出了一种多天线OFDM系统前导结构,用于实现时间、频率突发同步方案,并可以用于信道估计。所提出算法的特点一是计算复杂度低;二是对OFDM符号累加求平均,可以提高同步精度;三是对LS信道估计的时域值进行截断,显著提高了噪声环境下的信道估计精度。 相似文献
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Theoretical analysis of a coaxially fed, electromagnetically coupled two-layer elliptical microstrip stacked antenna based on circuit theory is presented in which mutual coupling is considered. Consequently, various parameters such as input impedance, VSWR, return loss, bandwidth etc. are investigated as a function of frequency, which shows resonance at 3.0GHz. It is also observed that there exists a critical value of frequency (3.0GHz) below which capacitive coupling is dominant and above which inductive coupling is dominant. The electromagnetic coupling enhances the radiated power which depends directly on the permittivity of the substrate, in spite of the fact that radiated power generally decreases with increasing permittivity of the substrate. 相似文献
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Davenport Demorest Culler Glenn J. Greaves John O. B. Forward Richard B. Hand William G. 《IEEE transactions on bio-medical engineering》1970,(3):230-237
Instrumentation is described which permits, along with simultaneous subjective observation, the rapid recording and quantification of the overt behavior of motile microorganisms under varying conditions. From a chain of standard commercially available units (with the exception of a single especially designed one) there has emerged a totality which provides unique advantages to the student of overt behavior. It consists of a primary optical system through which the organisms are televised, a standard video tape recorder, a unit which we have christened the ``bugwatcher' that processes the video signal from the tape for quantification of data by a computer, and finally, a digital computer. 相似文献
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Accurately identifying cloud types in images has multiple uses from meteorological science to computer graphics, especially as clouds are a major factor influencing atmospheric radiative transport. Understanding which cloud types are present in an image is typically performed on a coarse scale, where cloud types are identified per image, but do not permit a finer, per-pixel granularity of labelling cloud types. This paper presents a novel approach which solves this problem via a per-pixel classification method for identifying cloud types based on High Dynamic Range imagery of skies. The proposed method requires minimal labelling of the training data, and utilizes a hierarchical patch-based feature extraction technique which describes the statistical and structural features about regions of the image. This enables the extraction of representative feature vectors which are used for subsequent labelling. This approach is the first to produce a per-pixel classification of cloud types from a single image, with an accuracy of 84%. Additionally, when applied to whole sky cloud classification, our results produce a 98.3% accuracy, which is competitive with the state-of-the-art. 相似文献