共查询到19条相似文献,搜索用时 187 毫秒
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在辐射源个体识别技术应用中,接收机指纹和发射机指纹相互影响相互耦合,造成辐射源指纹库依赖于特定接收机,无法在不同接收机之间通用。针对此问题,对典型超外差接收机的滤波器、放大器畸变分量对接收信号指纹的影响进行了理论分析与实验验证。理论分析证明发射机和接收机的滤波器、放大器分量对于接收信号整体的畸变影响是等价的;实验中,利用两台超外差接收机对5台发射机进行个体识别测试验证,更换接收机前后,滤波器、放大器特征识别正确率分别从100%、95.5%降到20%,证明了接收机畸变分量对发射机指纹识别具有严重影响。该研究成果可为后续辐射源个体识别接收机设计以及接收机畸变校正提供理论依据。 相似文献
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信号的指纹特征是辐射源个体识别的重要依据。针对敌我识别辐射源的个体识别问题,提出了一种基于双树复小波和多重分形的信号暂态特征提取方法。该方法通过双树复小波变换实现信号多分辨率分解,求解分解信号Hilbert谱的信息熵和指数熵,计算信号的多重分形奇异指数和谱值,最终组成表征辐射源的特征向量。通过实验验证,提取的特征向量能充分代表辐射源个体之间的差异;被测信号的信噪比满足8 dB或9 dB的条件时,对辐射源的识别正确率能达到90%以上。统计分析表明该方法提取的特征具有很高的稳定性。 相似文献
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在对辐射源个体识别技术向组网协同方向发展的趋势进行探讨的基础上,提出了基于跨手段异类传感器组网协同的辐射源个体识别技术架构,分析了需要研究的基于传感器能力特性的协同识别、多维度信号特征关联融合、基于元数据的智能数据处理等关键问题。 相似文献
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针对复杂电磁环境下辐射源识别率低的问题,提出基于对角切片特征和深度学习的辐射源识别算法。利用辐射源信号双谱的个体特性,提取信号双谱对角切片特征作为深度学习模型的输入数据,采用Softmax分类器进行辐射源识别。仿真实验利用两部同型辐射源进行测试,结果表明该算法能识别个体辐射源,在低信噪比条件下也能获得高的辐射源识别率;相比于其他识别算法,双谱对角切片特征有更鲁棒的分辨性。 相似文献
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针对辐射源目标精确识别需求,结合以深度学习为代表的机器学习理论技术,提出将改进型AlexNet作为特征提取器,实现目标细微特征提取固化,形成智能化识别网络模型。以广播式自动相关监视(ADS-B)信号为实验对象,在机场实地采集了13个目标的ADS-B脉冲信号数据作为辐射源目标个体识别的训练和测试样本,利用AlexNet和改进的AlexNet验证了算法的有效性。结果表明,改进的AlexNet网络训练时间更快,综合识别率达到98.32%. 相似文献
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通过分析生成On-Off Keying(OOK)信号的发射机系统的幅度调制畸变特性,阐明了OOK信号辐射源特征产生机理,建立了OOK辐射源的幅度调制畸变特性的Wiener模型,并根据信号模型应用差分进化算法完成OOK幅度畸变特性参数的估计,从而构建辐射源指纹特征完成对OOK信号辐射源的识别。仿真试验和实际数据测试表明,该算法具备OOK辐射源指纹特征提取和识别能力,对实测数据中4个OOK辐射源识别率为93%,优于基于暂态幅度特征的提取方法。 相似文献
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利用辐射源目标的频移动态特征进行盲分选时,针对已有的分选方法不能很好解决非合作接收数据非周期、间断、交叠的问题,提出了一种改进的逻辑回归分选算法,将信号分选转化为轨迹分类的问题来处理。首先,借鉴多目标航迹起始模型中的M/N逻辑法的框架,设计新的数据关联门限,以建立目标起始曲线;其次,采用最小二乘拟合方法替代卡尔曼滤波,设计新的外推规则,建立载频变化预测曲线;分析新的接收数据与预测曲线的关联性,不断迭代回归或形成新的分支,最后获得目标分选结果。仿真与实测试验表明,利用逻辑回归分选算法,对不同运动目标搭载的同频辐射源可进行自动分选,4个仿真目标与2个真实目标的分选正确率达到100%。同时,该方法拓展了辐射源目标盲分选中的动态频移特征应用,为辐射源个体识别提供了新的支持。 相似文献
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支撑向量机(Support Vector Macbinc,SVM)是一种新的统计学习方法,作为一种说话人识别的手段具有独特的优势.通过产生的支持向量来概括数据集合中的信息,其分类核函数仅依赖于一小部分训练样本,即支持向量,从而降低信息的采集量和识别时间.本文介绍了说话人识别的基本原理,特征提取、模型训练等方面,通过实验证明支撑向量机(SVM)在说话人识别系统应用中表现出的良好性能. 相似文献
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论述了机载信息融合的典型需求及其应用现状,从理论研究和工程应用两个方面综述
了信息融合的模型结构,并提出适合未来作战飞机的动态信息融合体系结构。系统地梳理了
时空预处理的相关概念,概括了空间配准算法的研究现状及优缺点,指出机载空间配准研究的
紧迫性。结合工程实践,指出目标相关、状态估计和目标识别等模块处理方式与策略的重要性
,并在此基础上归纳总结了模块处理算法,对机载信息融合算法研究及工程实践有一定的指
导作用。 相似文献
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Karine Picot-Coupey 《International Review of Retail, Distribution & Consumer Research》2013,23(2):215-237
Abstract More and more retailers have expanded internationally. Because of its impact on the success of a retailer's international operations, a critical aspect of an internationalisation strategy consists of choosing the appropriate entry and expansion modes. The phenomenon remains misunderstood as little research in international retailing has focused on this question and findings from international management literature find limited application to services. This paper draws upon a literature review and six case-studies from French specialised retailers to provide an exploratory framework for examining key determinants of operation mode choice. It is found that retailers consider four underlying dimensions of operation modes. These dimensions are affected by situational, individual and marketing factors whose explanatory impacts are moderated by the motives for internationalisation and relationship networks. 相似文献
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Madhumita Paul Indrajit Ghosh 《International journal of injury control and safety promotion》2020,27(2):121-135
AbstractUnsignalized intersections in developing countries experience many serious conflicts between cross-traffic due to indiscipline traffic manoeuvrability. Historically, Post Encroachment Time (PET) has gained attention as a proximal indicator to analyze crossing conflicts. However, identifying an appropriate PET threshold to classify critical conflicts for highly heterogeneous traffic scenario is still an unexplored area. Consequently, this study proposes a novel approach of PET threshold identification with proof of application by collecting data from ten intersections located on four-lane intercity highways in the National Capital Region (NCR), India. Both crossing conflicts and right-turn related crash data (for the left-hand drive) are collected. Their correlations are thoroughly studied for each PET threshold using a quantitative technique considering all and individual vehicle categories. Finally, a qualitative analysis is done by ranking the sites based on cumulative PET and related crashes to verify the proposed quantitative technique. A PET threshold of 1?s is obtained from both the techniques which can be used to identify critical conflicts for unsignalized intersections located on four-lane intercity highways. The proposed methodology will serve as an alternative, faster and effective tool to evaluate the hazardousness of unsignalized intersections located on intercity highways under highly heterogeneous traffic condition. 相似文献
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Cory Searcy 《Journal of Business Ethics》2012,107(3):239-253
Corporate sustainability performance measurement systems (SPMS) have been the subject of a growing amount of research. However,
there are many challenges and opportunities associated with the design, implementation, use, and evolution of these systems
that have yet to be addressed. The purpose of this article is to identify future directions for research in the design, implementation,
use, and evolution of corporate SPMS. A concise review of key literature published between 2000 and 2010 is presented. The
literature review focuses on research conducted at the both the individual corporation- and sector-levels. The review of published
literature provides a basis for the identification of a structured set of 65 key research questions to guide future work.
The research questions will be of interest to both practitioners and researchers in corporate sustainability performance measurement. 相似文献
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Mike T. Bendixen 《Journal of Marketing Management》2013,29(6):571-581
The construction of compositional perceptual maps is an important aspect of the management of brands. The use of correspondence analysis to construct such maps is not new, nor is the subsequent use of conventional hierarchical and non‐hierarchical cluster analysis to segment the brands. However, the application of chi‐squared trees analysis can be used to cluster both brands and attributes using the same principle of decomposing the χ2 statistic of the matrix of frequency of responses as in correspondence analysis. Used in conjunction, these two techniques allow the construction of an enriched compositional perceptual map. 相似文献