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基于多域积累的弱信号检测方法
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作者 刘乐 薛坚 黄桂根 《空天预警研究学报》 2025年第5期329-332,共4页
针对复杂电磁环境对电子侦察距离提升需求,提出了一种基于多域积累的弱信号检测方法.该方法综合利用信道化处理、循环自相关、非相参积累对信号进行多域处理,实现多域信号能量积累,进而提升信号的检测得益.最后通过仿真试验,验证了本文... 针对复杂电磁环境对电子侦察距离提升需求,提出了一种基于多域积累的弱信号检测方法.该方法综合利用信道化处理、循环自相关、非相参积累对信号进行多域处理,实现多域信号能量积累,进而提升信号的检测得益.最后通过仿真试验,验证了本文方法的有效性.仿真结果表明,在输入信噪比为-17 dB的条件下,本文方法的信号检测概率可达到93%,且具有更高的检测灵敏度. 展开更多
关键词 电子侦察 弱信号检测 信道化 循环自相关 非相参积累
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100G Transport Systems: Technology Bench-Mark Testing in China and Evolution to Terabit/s Interfaces 被引量:1
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作者 张晓宏 易小波 +1 位作者 刘翔 Peter J.Winzer 《China Communications》 SCIE CSCD 2013年第4期19-30,共12页
To meet the exponentially growing demand fbr bandwidth in Optical Transport Networks (OTNs), 100-Gb/s (100G) coherent technology based oil Polarization-Division Multiplexed Quadrature Phase Shift Keying (PDM-QPSK... To meet the exponentially growing demand fbr bandwidth in Optical Transport Networks (OTNs), 100-Gb/s (100G) coherent technology based oil Polarization-Division Multiplexed Quadrature Phase Shift Keying (PDM-QPSK), which enables the capacity of a Wavelength Division Multiplexing (WDM) system to approach 10 Tb/s, is being widely deployed globally. As the first vendor to intro- duce a single-carrier 100G solution, A1- catel-Lucent has developed key transponder and network management technologies, which are reviewed in this paper together with their commercial evolution to 400G. Focusing on the Chinese market, we also review some key bench-mark testing results obtained in partner- ship with major Chinese operators. Finally, we discuss enabling technologies that are currently being researched to allow interfaces to scale to Terabit/s rates. 展开更多
关键词 WDM transmission digital co-herent detection advanced modulation for-mats: wavelength monitoring superchannel
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Simulated Annealing for Land Cover Classification in PolSAR Images
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作者 Georgia Koukiou 《Advances in Remote Sensing》 2022年第2期49-61,共13页
Simulated Annealing (SA) is used in this work as a global optimization technique applied in discrete search spaces in order to change the characterization of pixels in a Polarimetric Synthetic Aperture Radar (PolSAR) ... Simulated Annealing (SA) is used in this work as a global optimization technique applied in discrete search spaces in order to change the characterization of pixels in a Polarimetric Synthetic Aperture Radar (PolSAR) image which have been classified with different label than the surrounding land cover type. Accordingly, Land Cover type classification is achieved with high reliability. For this purpose, an energy function is employed which is minimized by means of SA when the false classified pixels are correctly labeled. All PolSAR pixels are initially classified using 9 specifically selected types of land cover by means of Google Earth maps. Each Land Cover Type is represented by a histogram of the 8 Cameron’s elemental scatterers by means of coherent target decomposition (CTD). Each PolSAR pixel is categorized according to the local histogram of the elemental scatterers. SA is applied in the discreet space of nine land cover types. Classification results prove that the Simulated Annealing approach used is very successful for correctly separating regions with different Land Cover Types. 展开更多
关键词 Land Cover Classification Simulated Annealing Fully Polarimetric SAR co-herent Decomposition Elemental Scatterers
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C波段4路磁控管相干功率合成微波源实验研究 被引量:2
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作者 冯永强 郭庆功 +1 位作者 张昊 王振力 《真空电子技术》 2014年第4期52-57,61,共7页
针对目前C波段磁控管存在的频率输出不稳定、相位输出随机移动、功率容量的物理限制等一系列问题,设计实现了基于注入锁频和反馈调相技术的C波段4路磁控管相干功率合成微波源。该微波源由三部分构成:4路独立注入锁定的磁控管单元,4路间... 针对目前C波段磁控管存在的频率输出不稳定、相位输出随机移动、功率容量的物理限制等一系列问题,设计实现了基于注入锁频和反馈调相技术的C波段4路磁控管相干功率合成微波源。该微波源由三部分构成:4路独立注入锁定的磁控管单元,4路间稳频、锁频、比相的反馈控制单元,测量及显示单元。为更好的对C波段4路磁控管相干功率合成微波源进行研究,在搭建的4路磁控管微波源的平台上,对直流高压源的纹波特性、磁控管的阳极电流、功放的注入功率、4路磁控管之间的相位控制等影响微波源输出特性的相关因素进行了实验研究。最终实现微波源工作带宽:5.788GHz±2MHz;频率稳定度:0.07%;相位调节范围:0°~360°;相位调节精度:±3°;相位噪声:-40dBc/Hz@1kHz;功率合成效率:94.74%;总输出功率】2000W。 展开更多
关键词 磁控管微波源 注入锁频 反馈调相 相干功率合成
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基于离散阵列流形的宽带聚焦方法
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作者 王珺琳 卞红雨 《华中科技大学学报(自然科学版)》 EI CAS CSCD 北大核心 2013年第10期45-48,共4页
针对相干信号子空间方法须要角度预估的缺陷,提出了一种无须角度预估的宽带聚焦方法.将最小二乘原理应用到矩阵运算中,用离散化的角度构造非奇异的阵列流形矩阵,从而求得聚焦矩阵,不仅无须角度预估,而且避免了阵列流形内插法中贝塞尔函... 针对相干信号子空间方法须要角度预估的缺陷,提出了一种无须角度预估的宽带聚焦方法.将最小二乘原理应用到矩阵运算中,用离散化的角度构造非奇异的阵列流形矩阵,从而求得聚焦矩阵,不仅无须角度预估,而且避免了阵列流形内插法中贝塞尔函数的计算,有效地降低了运算复杂度.计算机仿真了均匀线列阵下提出方法的方位估计性能,结果表明本方法比阵列流形内插法具有更好的方位估计性能和更短的运算时间. 展开更多
关键词 信号处理 阵列处理 方位估计 聚焦 宽带相干源 阵列流形 内插方法
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Current Status of Intra-Vascular Imaging during Coronary Interventions
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作者 Sridhar Kasturi 《World Journal of Cardiovascular Diseases》 2021年第8期389-419,共31页
Most important interventional application of IVUS is plaque assessment, vessel sizing and stent implantation guidance. Image guided PCI </span></span><span style="white-space:normal;">... Most important interventional application of IVUS is plaque assessment, vessel sizing and stent implantation guidance. Image guided PCI </span></span><span style="white-space:normal;"><span style="font-family:"">is </span></span><span style="white-space:normal;"><span style="font-family:"">associated with decreased incidence of stent thrombosis and MACE rate as evident in recently published meta-analysis of IVUS guided PCI studies. Many imaging studies have shown very clearly under-expansion, edge-dissection, tissue-prolapse, mal apposition, and geographical miss are associated with adverse events following DES implantation, and IVI guides in optimization of stent implantation by identifying and rectifying these predictors of DES outcomes. 展开更多
关键词 Left-Main Coronary Artery Imaging Intra-Vascular Ultra-Sound Optical co-herence Tomography
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Rapid Plaque Progression in a Patient with Non-ST-Segment Elevation Acute Coronary Syndrome: A Case Report
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作者 Yachao Li Mengjie Lei +3 位作者 Jingyao Wang Yanli Yang Zhigang Zhao Zengming Xue 《Cardiovascular Innovations and Applications》 2024年第1期28-36,共9页
Acute coronary syndrome(ACS),diagnosed by optical coherence tomography(OCT),is caused primarily by plaque rupture,plaque erosion,and calcified nodules.Plaque erosion is more common in patients with non-ST-segment elev... Acute coronary syndrome(ACS),diagnosed by optical coherence tomography(OCT),is caused primarily by plaque rupture,plaque erosion,and calcified nodules.Plaque erosion is more common in patients with non-ST-segment eleva-tion myocardial infarction than ST-segment elevation myocardial infarction.This study reports the details of a case of ACS caused by massive thrombus formation due to plaque erosion.The factors associated with plaque erosion and thrombosis could not be confirmed on the basis of clinical examination findings and the physicians’experience;there-fore,the initial diagnosis of an ischemic event was replaced by a diagnosis of rapid plaque progression,as microscopi-cally confirmed by OCT.Therefore,OCT examination must be performed for blurred or“rapidly progressing”lesions identified through angiography. 展开更多
关键词 Non-ST-segment elevation acute coronary syndrome Plaque erosion Organized thrombus Optical co-herence tomography
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