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IRS辅助无人机通信系统的物理层安全研究综述 被引量:2
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作者 王正强 孔维冬 +1 位作者 万晓榆 樊自甫 《无线电工程》 2025年第6期1133-1143,共11页
近年来,UAV因其高灵活性和广泛的应用场景,在现代通信网络中扮演着重要角色。由于UAV通信链路通常处于开放空域,极易受到窃听和恶意干扰的威胁,物理层安全(Physical Layer Security,PLS)问题亟待解决。作为一种新型的二维人工电磁表面,... 近年来,UAV因其高灵活性和广泛的应用场景,在现代通信网络中扮演着重要角色。由于UAV通信链路通常处于开放空域,极易受到窃听和恶意干扰的威胁,物理层安全(Physical Layer Security,PLS)问题亟待解决。作为一种新型的二维人工电磁表面,智能反射面(Intelligent Reflecting Surface,IRS)由大量具有特殊设计的被动散射单元组成,能够对信号反射路径进行智能调控,为改善信道环境和增强物理层安全提供了全新的技术手段。因此,IRS在UAV通信中的应用引起了广泛关注,为解决开放空域中的通信安全问题提供了新的方向。通过对现有的国内外文献进行梳理,主要从保密速率(Secrecy Rate,SR)、保密能效(Secrecy Energy Efficiency,SEE)和保密中断概率(Secrecy Outage Probability,SOP)三方面概述了地面固定IRS系统和UAV搭载IRS系统在PLS领域的研究现状。分析了当前研究存在的不足,展望了IRS辅助UAV通信系统在PLS领域的未来研究方向。 展开更多
关键词 UAV 物理层安全 智能反射面 保密速率 保密能效 保密中断概率
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The dynamics beamline at SSRF 被引量:1
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作者 Zhen Liu Li-Hua Wang +6 位作者 Yong Jiang Ya-Jun Tong Hua-Chun Zhu Te Ji Min Chen Zheng Jiang Xiang-Jun Wei 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第9期56-67,共12页
The dynamics beamline(D-Line),which combines synchrotron radiation infrared spectroscopy(SR-IR)and energy-disper-sive X-ray absorption spectroscopy(ED-XAS),is the first beamline in the world to realize concurrent ED-X... The dynamics beamline(D-Line),which combines synchrotron radiation infrared spectroscopy(SR-IR)and energy-disper-sive X-ray absorption spectroscopy(ED-XAS),is the first beamline in the world to realize concurrent ED-XAS and SR-IR measurements at the same sample position on a millisecond time-resolved scale.This combined technique is effective for investigating rapid structural changes in atoms,electrons,and molecules in complicated disorder systems,such as those used in physics,chemistry,materials science,and extreme conditions.Moreover,ED-XAS and SR-IR can be used independently in the two branches of the D-Line.The ED-XAS branch is the first ED-XAS beamline in China,which uses a tapered undulator light source and can achieve approximately 2.5×10^(12)photons/s·300 eV BW@7.2 keV at the sample position.An exchange-able polychromator operating in the Bragg-reflection or Laue-transmission configuration is used in different energy ranges to satisfy the requirements for beam size and energy resolution.The focused beam size is approximately 3.5μm(H)×21.5μm(V),and the X-ray energy range is 5–25 keV.Using one-and two-dimensional position-sensitive detectors with frame rates of up to 400 kHz enables time resolutions of tens of microseconds to be realized.Several distinctive techniques,such as the concurrent measurement of in situ ED-XAS and infrared spectroscopy,time-resolved ED-XAS,high-pressure ED-XAS,XMCD,and pump-probe ED-XAS,can be applied to achieve different scientific goals. 展开更多
关键词 ED-XAS sr-ir TIME-RESOLVED D-line SSRF
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毫米波/红外多传感器融合跟踪算法研究 被引量:15
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作者 潘勃 冯金富 +1 位作者 李骞 李斌 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2010年第3期230-235,共6页
毫米波/红外(MMW/IR)传感器是各国发展多模复合制导技术的重点.针对平方根无迹卡尔曼滤波(SR-UKF)的估计算法存在线性化误差及粒子滤波中得到优化的重要性密度函数比较困难的问题,将平方根无迹卡尔曼滤波与粒子滤波相结合,提出一种序贯... 毫米波/红外(MMW/IR)传感器是各国发展多模复合制导技术的重点.针对平方根无迹卡尔曼滤波(SR-UKF)的估计算法存在线性化误差及粒子滤波中得到优化的重要性密度函数比较困难的问题,将平方根无迹卡尔曼滤波与粒子滤波相结合,提出一种序贯融合的平方根无迹卡尔曼粒子滤波(SR-UK-PF)算法.利用平方根无迹卡尔曼算法得到的状态更新矩阵和误差协方差矩阵,构造粒子滤波的重要性密度函数,这样重要性密度函数能够融入最新观测信息,进而更加符合真实状态的后验概率分布.为验证算法的有效性,以地空导弹中MMW/IR传感器复合制导为背景进行仿真研究与分析,结果表明,该算法克服了粒子滤波法难以得到优化重要性密度函数的缺陷,能有效提高多传感器系统状态估计的精度. 展开更多
关键词 毫米波/红外 闪烁噪声 平方根无迹卡尔曼滤波 粒子滤波 重要性密度函数
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Synthesis and Characterization of IR Up-Conversion Material SrS∶Eu, Sm 被引量:1
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作者 卢利平 张希艳 +3 位作者 柏朝晖 王晓春 米晓云 刘全生 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第S1期44-47,共4页
Europium and samarium co-doped strontium sulfide (SrS∶Eu, Sm) infrared up-conversion phosphor was synthesized through calcining the precursor, which prepared by wet-method with strontium carbonate (SrCO_3), sulphur (... Europium and samarium co-doped strontium sulfide (SrS∶Eu, Sm) infrared up-conversion phosphor was synthesized through calcining the precursor, which prepared by wet-method with strontium carbonate (SrCO_3), sulphur (S), europium oxide (Eu_2O_3) and samarium oxide (Sm_2O_3) as the starting materials, lithium fluoride (LiF) as the fluxing agent, at 750~1200 ℃ in carbon-reducing atmosphere. XRD analysis shows that SrS crystal structure is formed at 750 ℃, most completely at 1100 ℃. The IR up-conversion luminescence properties were characterized by excitation, emission, up-conversion excitation, up-conversion emission and thermoluminescence spectra. The spectral analysis associated with the physical model of up-conversion luminescence shows that the IR up-conversion luminescence is resulted from electron trapping process of Sm 3+ energy level. The thermoluminescence peak does not appear below 500 ℃ indicating the trapping energy level is appropriately deep, 800~1400 nm near infrared light can be the release light to realize up-conversion luminescence. 展开更多
关键词 SrS∶ Eu Sm PHOSPHOR IR up-conversion luminescence wet-method rare earths
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Edge preserving super-resolution infrared image reconstruction based on L1-and L2-norms 被引量:1
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作者 Shaosheng DAI Dezhou ZHANG +2 位作者 Junjie CUI Xiaoxiao ZHANG Jinsong LIU 《Frontiers of Optoelectronics》 EI CSCD 2017年第2期189-194,共6页
Super-resolution (SR) is a widely used tech- nology that increases image resolution using algorithmic methods. However, preserving the local edge structure and visual quality in infrared (IR) SR images is challeng... Super-resolution (SR) is a widely used tech- nology that increases image resolution using algorithmic methods. However, preserving the local edge structure and visual quality in infrared (IR) SR images is challenging because of their disadvantages, such as lack of detail, poor contrast, and blurry edges. Traditional and advanced methods maintain the quantitative measures, but they mostly fail to preserve edge and visual quality. This paper proposes an algorithm based on high frequency layer features. This algorithm focuses on the IR image edge texture in the reconstruction process. Experimental results show that the mean gradient of the IR image reconstructed by the proposed algorithm increased by 1.5, 1.4, and 1.2 times than that of the traditional algorithm based on L1- norm, L2-norm, and traditional mixed norm, respectively. The peak signal-to-noise ratio, structural similarity index, and visual effect of the reconstructed image also improved. 展开更多
关键词 infrared (IR) super-resolution (SR) image reconstruction high frequency layer edge texture
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