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Moving target detection in the cepstrum domain for passive coherent location (PCL) radar

Ji-chuan LI,Xiao-de LU,Hui ZHANG,Peng-cheng YANG,Yu LIU,Mao-sheng XIANG

《信息与电子工程前沿（英文）》 2015年第16卷第9期页码 785-795 doi: 10.1631/FITEE.1500036

摘要： A cepstrum moving target detection (CEPMTD) algorithm based on cepstrum techniques is proposed for passive coherent location (PCL) radar systems. The primary cepstrum techniques are of great success in recognizing the arrival times of static target echoes. To estimate the Doppler frequencies of moving targets, we divide the radar data into a large number of segments, and reformat these segments into a detection matrix. Applying the cepstrum and the Fourier transform to the fast and slow time dimensions respectively, we can obtain the range information and Doppler information of the moving targets. Based on the CEPMTD outlined above, an improved CEPMTD algorithm is proposed to improve the detection performance. Theoretical analyses show that only the target’s peak can be coherently added. The performance of the improved CEPMTD is initially validated by simulations, and then by experiments. The simulation results show that the detection performance of the improved CEPMTD algorithm is 13.3 dB better than that of the CEPMTD algorithm and 6.4 dB better than that of the classical detection algorithm based on the radar cross ambiguity function (CAF). The experiment results show that the detection performance of the improved CEPMTD algorithm is 1.63 dB better than that of the radar CAF.

关键词： Moving target detection Cepstrum techniques Cross ambiguity function (CAF) Passive coherent location (PCL) radar

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单站无源定位可观测性评述

邓新蒲

《中国工程科学》 2007年第9卷第11期页码 54-62

摘要：

可观测性分析是单观测器无源定位首先要研究的问题，只有当目标状态 (位置、速度等)是完全可观测的，定位和跟踪问题才能有可靠的、唯一的解。从几何方法、代数方程方法、线性系统方法3方面来阐述单站测角无源定位的状态可观性问题，讨论测频单站无源定位问题的可观测性和定量的可观测性，并对近年来这一领域的相关文献的分析方法和结论进行评述。

关键词：无源定位 TMA 可观测性

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基于位置旋转变换和非均匀快速傅立叶变换的机动目标高效相参检测 Research Articles

靳科1,赖涛2,齐艳丽3,黄洁1,赵拥军1

《信息与电子工程前沿（英文）》 2020年第21卷第8期页码 1251-1266 doi: 10.1631/FITEE.1900272

摘要：长时间相参积累能够显著提升雷达对机动目标的检测和运动参数估计性能。然而，相参积累期间目标的线性距离徙动、二次距离徙动和多普勒频率徙动将导致检测性能急剧下降。提出基于位置旋转变换和非均匀快速傅里叶变换的高效稳健相参积累方法。首先，利用二阶Keystone变换消除二次距离徙动。然后，利用旋转角度和多普勒频率之间的对应关系，构建相位补偿函数，从而利用位置旋转和非均匀快速傅里叶变换实现高效的参数估计。与现有代表性算法相比，所提算法能以较低运算复杂度实现近乎理想的检测性能。最后，基于雷达实测数据的实验证明所提算法有效。

关键词：相参积累；机动目标；参数估计；位置旋转变换；非均匀快速傅立叶变换

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无源互调测量——挑战与解决方案 Review

蔡张华, 刘列, Francesco de Paulis, 漆一宏

《工程（英文）》 2022年第14卷第7期页码 181-191 doi: 10.1016/j.eng.2022.02.012

摘要：

在现代无线通信系统中，信噪比（SNR）是最重要的性能指标之一。当部件的其他射频（RF）性能设计良好时，无源互调（PIM）干扰可能成为限制系统SNR的重要因素。无论是基站、室内分布式天线系统还是卫星系统，都存在严格的PIM级别要求，以最大程度地减少干扰并增强多载波网络中的网络容量。尤其是5G无线通信等大功率、大带宽的系统，PIM干扰更严重。由于无源互调的复杂性和不确定性，测量是研究和评估无线通信系统无源互调性能的最重要手段。本文介绍了国际电工委员会（IEC）等标准组织推荐的当前主要PIM 测量方法，以及PIM 测量中的几个关键挑战及其解决方案（包括PIM 测试仪的设计、
PIM源的定位、紧凑型PIM暗室的设计，以及PIM暗室的评估方法）。这些挑战对于解决实际无线通信系统中设备可能出现的PIM问题具有重要意义。

关键词：无源互调 (PIM) PIM源定位消声室

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基于迭代方法的联合压缩感知与相位修正多站外辐射源雷达成像算法研究 None

Jue WANG, Jun WANG

《信息与电子工程前沿（英文）》 2018年第19卷第4期页码 557-568 doi: 10.1631/FITEE.1601423

摘要：受限于机会照射源信号通常为窄带信号，多站外辐射源雷达成像系统分辨率通常较低。另外，由于跟踪系统精度影响及站址测量过程中存在测量误差，系统成像质量会严重下降。为提高多站外辐射源雷达成像系统成像性能，开展了基于层析成像原理的高分辨外辐射源雷达成像算法研究。进一步，将压缩感知技术应用于外辐射源雷达成像系统中，以改善系统成像分辨力。最后，针对非合作平台测量误差引入的相位误差，提出相应的外辐射源雷达成像系统相位补偿方法。通过最小化图像的重构误差建立了相位误差求解模型，基于定点迭代技术对相位误差模型求解。所提相位误差补偿技术是一种非参数化方法，可用于补偿任意形式相位误差。理论分析与仿真实验验证了所提方法的有效性和收敛性。

关键词：多站外辐射源雷达；压缩感知；相位修正；定点迭代技术

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基于深度前馈神经网络的多基地外辐射源雷达高精度目标跟踪 Research Article

徐宝兄,易建新,程丰,龚子平,万显荣

《信息与电子工程前沿（英文）》 2023年第24卷第8期页码 1214-1230 doi: 10.1631/FITEE.2200260

摘要：在雷达系统中，目标跟踪误差主要来自运动模型和非线性量测。在评估跟踪算法时，其跟踪精度是主要衡量准则。为提高跟踪精度，本文将跟踪问题表述为从量测到目标状态的回归模型，提出一种基于改进深度前馈神经网络（MDFNN）的跟踪算法。所提MDFNN跟踪算法引入一种滤波层来描述输入量测序列的时序关系，并分析了最优量测序列长度。仿真和实测的外辐射源雷达数据测试表明，在所考虑的场景下，所提算法跟踪精度优于基于扩展卡尔曼滤波器（EKF）、无迹卡尔曼滤波器（UKF）和递归神经网络（RNN）的跟踪方法。

关键词：深度前馈神经网络；滤波层；外辐射源雷达；目标跟踪；跟踪精度

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Effect of incorporating Elaeagnus angustifolia extract in PCL-PEG-PCL nanofibers for bone tissue engineering

Vahideh R. Hokmabad, Soodabeh Davaran, Marziyeh Aghazadeh, Effat Alizadeh, Roya Salehi, Ali Ramazani

《化学科学与工程前沿（英文）》 2019年第13卷第1期页码 108-119 doi: 10.1007/s11705-018-1742-7

摘要：

Plants have been used for medicinal purposes for thousands of years but they are still finding new uses in modern times. For example, Elaeagnus angustifolia (EA) is a medicinal herb with antinociceptive, anti-inflammatory, antibacterial and antioxidant properties and it is widely used in the treatment of rheumatoid arthritis and osteoarthritis. EA extract was loaded onto poly(ϵ-caprolactone)-poly(ethylene glycol)-poly(ϵ-caprolactone) (PCL-PEG-PCL/EA) nanofibers and their potential applications for bone tissue engineering were studied. The morphology and chemical properties of the fibers were evaluated using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, contact angle measurements and mechanical tests. All the samples had bead-free morphologies with average diameters ranging from 100 to 200 nm. The response of human cells to the PCL-PEG-PCL/EA nanofibers was evaluated using human dental pulp stem cells (hDPSCs). The hDPSCs had better adhesion and proliferation capacity on the EA loaded nanofibers than on the pristine PCL-PEG-PCL nanofibers. An alizarin red S assay and the alkaline phosphatase activity confirmed that the nanofibrous scaffolds induced osteoblastic performance in the hDPSCs. The quantitative real time polymerase chain reaction results confirmed that the EA loaded nanofibrous scaffolds had significantly upregulated gene expression correlating to osteogenic differentiation. These results suggest that PCL-PEG-PCL/EA nanofibers might have potential applications for bone tissue engineering.

关键词： Elaeagnus angustifolia scaffold electrospinning human dental pulp stem cell tissue engineering

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外辐射源雷达中基于最差性能最优的稳健失配滤波算法 Research Articles

陈刚,王俊

《信息与电子工程前沿（英文）》 2020年第21卷第7期页码 963-1118 doi: 10.1631/FITEE.1900150

摘要：外辐射源雷达利用可获得的民用及商用照射源探测目标。这些照射源信号并非为雷达设计，信号结构中存在的时变特性使其模糊函数存在严重的距离模糊副峰。失配滤波技术能有效抑制副峰，可应用于外辐射源雷达。然而，当参考信号信噪比较低时，外辐射源雷达系统的副峰抑制性能急剧下降。为解决该问题，提出一种基于最差性能最优的失配滤波算法。该算法考虑参考信号信噪比的影响，据此构建新的优化问题模型。通过求解该优化问题，可得低参考信号信噪比情况下的最优失配解。理论推导和仿真分析说明所提算法可在较低参考信号信噪比情况下实现副峰抑制。实测数据进一步验证了该方法的有效性。

关键词：外辐射源雷达；距离副峰；低信噪比；失配滤波；最差性能最优

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On the potential of iPhone significant location data to characterize individual mobility for air pollution

《环境科学与工程前沿（英文）》 2022年第16卷第5期 doi: 10.1007/s11783-022-1542-7

摘要：

● We evaluated the accuracy of iPhone data in capturing time-activity patterns.

关键词： Air pollution exposure Human mobility iPhone Significant Location Smartphone data

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Space-time evolution rules study on acoustic emission location in rock under cyclic loading

Jiang XU, Shuchun LI, Yunqi TAO, Yongdong JIANG, Xiaojun TANG,

《结构与土木工程前沿（英文）》 2009年第3卷第4期页码 422-427 doi: 10.1007/s11709-009-0056-8

摘要： An acoustic emission (AE) location experiment was performed on sandstone using an advanced AE test system. The space-time evolution rule regarding damage was analyzed under cyclic loading as well as AE. The results show that AE on static loading process is consistent with the damage evolution rule of compression and the elastic-plastic deformation phase; at the beginning of cyclic loading with low duration time and energy, AE events came from a small crack. The location result showed that most events occurred in the core zone forming at the static loading process, and the location points changed slowly. AE energy changed little during the metaphase of cyclic process. There was a modest increase of location points in every cycle. The tendency of steady development could be predicted from the AE location events. At the end of each cyclic loading, the quantity of AE events and energy increased quite rapidly, reaching a maximum at the last cycle. AE events had high energy and duration time. Location events changed quite rapidly and assembled and linked continuously in the core zone. At the same time, they expanded to the top of specimen. A macroscopic crack finally formed. In the postfailure process, some AE events still existed due to fracturing of gliding friction. Owing to the inner stress balance of rock even after loading stopped, minor AE events still occurred.

关键词： location result AE location consistent friction elastic-plastic deformation

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压力梯度作用下相干结构的演化

陆利蓬,李兆瑞

《中国工程科学》 2002年第4卷第11期页码 50-56

摘要：

采用共振三波的一个周期作为湍流边界层近壁区相干结构的初值，用直接数值模拟方法对有压力梯度，包括定常压力梯度和变压力梯度作用下相干结构的演化进行了研究，得出其各种特性的变化与实验观测到的结果一致。压力梯度对相干结构初始扰动波的选择以及演化过程都起作用，相比之下对前者的作用更大。条纹结构和流向涡之间有某种内在的紧密的联系，可能是产生流向涡的起因。

关键词：相干结构湍流边界层压力梯度直接数值模拟

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Mechanistic insight into the biofilm formation and process performance of a passive aeration ditch (PAD

《环境科学与工程前沿（英文）》 2022年第16卷第7期 doi: 10.1007/s11783-021-1494-3

摘要：

• A Passive Aeration Ditch was developed to treat decentralized wastewater.

关键词： Decentralized wastewater Passive aeration ditch Biofilm formation C/N ratio Salinity Model simulation

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海洋二号卫星主被动微波遥感探测技术研究

蒋兴伟,林明森,宋清涛

《中国工程科学》 2013年第15卷第7期页码 4-11

摘要：

介绍了海洋二号（HY-2A）卫星4个微波有效载荷（雷达高度计、微波散射计、扫描微波辐射计和校正微波辐射计）的功能、性能和设计指标。HY-2A卫星突破了我国微波遥感设备技术上的瓶颈，为海洋环境监测预报业务化和防灾减灾提供了必要的海洋观测手段，解决了我国自主海洋动力环境参数遥感观测有无的问题。HY-2A卫星的成功发射和业务化运行为我国海洋卫星发展规划打下了坚实的基础。

关键词： HY-2A卫星微波遥感海洋遥感雷达高度计微波散射计微波辐射计

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Numerical modeling and performance evaluation of passive convergence-permeable reactive barrier (PC-PRB

《环境科学与工程前沿（英文）》 2023年第17卷第11期 doi: 10.1007/s11783-023-1731-z

摘要：

● A 2D finite-element solute transport model, PRB-Trans, is developed.

关键词： Passive convergence-permeable reactive barrier Numerical modeling Hydraulic behavior assessment Pollutant treatment performance evaluation Influential factors analysis

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Research and application of visual location technology for solder paste printing based on machine vision

Luosi WEI, Zongxia JIAO

《机械工程前沿（英文）》 2009年第4卷第2期页码 184-191 doi: 10.1007/s11465-009-0034-9

摘要： A location system is very important for solder paste printing in the process of surface mount technology (SMT). Using machine vision technology to complete the location mission is new and very efficient. This paper presents an integrated visual location system for solder paste printing based on machine vision. The working principle of solder paste printing is introduced and then the design and implementation of the visual location system are described. In the system, two key techniques are completed by secondary development based on VisionPro. One is accurate image location solved by the pattern-based location algorithms of PatMax. The other one is camera calibration that is achieved by image warping technology through the checkerboard plate. Moreover, the system can provide good performances such as high image locating accuracy with 1/40 sub-pixels, high anti-jamming, and high-speed location of objects whose appearance is rotated, scaled, and/or stretched.

关键词： machine vision visual location solder paste printing VisionPro