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Progressive iterative channel estimation in fast time-varying OFDM systems

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The Journal of China Universities of Posts and Telecommunications 2014年第4期21卷 8-14页

作者： yanG Rui-zhe YE Si-yang ZHANG yan-hua sun yan-hua YU Richard College of Electronics Information and Control Engineering Beijing University of Technology Department of Systems and Computer Engineering Carleton University

Considering the joint channel estimation and data detection in time-varying orthogonal frequency division multiplexing （OFDM） and addressing transmission performance degradation induced by the severe inter-carrier interference （ICI） at very high speed, a new progressive iterative channel estimation scheme is proposed. To alleviate the error propagation of the inaccurate data due to ICI, the measurement subcarriers in the Kalman filter is designed to be extended from pilots subcarriers to all the subcarriers progressively through the iterations. Furthermore, in iteration process, the interference of the non-pilot data to the measurement subcarriers is considered to be part of noise in the modified Kalman filter, which improves the estimation accuracy. Simulation indicates that the proposed scheme improves the performance in fast time-varying situation.

关键词： time-varying OFDM channel estimation ICI progressive Kalman

An Approximate Analytical Propagation Formula for Gaussian Beams through a Cat-Eye Optical Lens under Large Incidence Angle Condition

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Chinese Physics Letters 2011年第7期28卷 114-117页

作者： ZHAO yan-Zhong sun hua-yan ZHENG Yong-Hui Academy of Equipment Command and Technology Beijing 101416

Based on the generalized diffraction integral formula and the idea that the angle misalignment of the cat-eye optical lens can be transformed into the displacement misalignment,an approximate analytical propagation formula for Gaussian beams through a cat-eye optical lens under large incidence angle condition is *** results show that the diffraction effect of the apertures of the cat-eye optical lens becomes stronger along with the increase in incidence *** results are also compared with those from using an angular spectrum diffraction integral and experiment to illustrate the applicability and validity of our theoretical *** is shown that the approximate extent is good enough for the application of a cat-eye optical lens with a radius of 20 mm and a propagation distance of 100 m,and the approximate extent becomes better along with the increase in the radius of the cat-eye optical lens and the propagation distance.

关键词： approximate radius Gaussian

Airway Management in a Child with Goldenhar Syndrome

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Chinese Medical Journal 2017年第23期130卷 2881-2882页

作者： yan-hua sun Bo Zhu Bing-yang Ji Xiu-hua Zhang Department of Anesthesiology Peking Union Medical College Hospital Beijing 100730 China Department of Cardiopulmonary Bypass Fuwai Hospital National Center for Cardiovascular Diseases Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100037 China

Goldenhar syndrome, also known as oculo-auriculo-vertebral dysplasia, is characterized by a wide range of congenital anomalies, such as micrognathia, oral cavity malformations, and vertebral anomalies and always causes difficult airway. Awake intubation often cannot be used on children because of inadequate cooperation. In addition, children have higher rates of oxygen consumption, significantly shortening the period of apnea that can be safely tolerated. This study reported a successful orotracheal intubation using the McGrath？ video laryngoscope combined with a fiberoptic bronchoscope （FOB） in a pediatric patient with Goldenhar syndrome.

关键词： Airway: Anesthesia: Goldenhar Syndrome

Three-Dimensional Analytical Formula for Oblique and Off-Axis Gaussian Beams Propagating through a Cat-Eye Optical Lens

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Chinese Physics Letters 2010年第3期27卷 128-131页

作者：赵延仲孙华燕喻夏琼樊萌山 Academy of Equipment Command and Technology Beijing 101416

Based on the Collins formula in a cylindrical coordinate system and the method of introducing a hard aperture function into a finite sum of complex Gaussian functions, an approximate three-dimensional analytical formula for oblique and off-axis Gaussian beams propagating through a cat-eye optical lens is derived. Numerical results show that a reasonable choice of the obliquity factor would result in a better focus beam with a higher central intensity at the return place than that without obliquity, whereas the previous conclusion based on geometry optics is that the highest central intensity could be obtained when there is no obliquity.

关键词： Mathematical physics Optics quantum optics and lasers

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复数域格缩减的MIMO检测算法研究

电子科技大学学报 2010年第5期39卷 670-675页

作者：孙艳华王浩张延华北京工业大学电控学院北京朝阳区100124 普天信息技术研究院有限公司北京海淀区100080

多入多出(MIMO)系统可以获得比单发单收系统更高的容量,对于MIMO系统,最大似然检测是最优接收,但其指数复杂度难以在实际中应用。针对该问题,结合格缩减理论提出了基于Householder变换的复数域格缩减算法,将该算法和MIMO次优检测算法相... 详细信息

多入多出(MIMO)系统可以获得比单发单收系统更高的容量,对于MIMO系统,最大似然检测是最优接收,但其指数复杂度难以在实际中应用。针对该问题,结合格缩减理论提出了基于Householder变换的复数域格缩减算法,将该算法和MIMO次优检测算法相结合,给出了量化判决方法,且该复数域格缩减算法复杂度小于实数域格缩减算法。仿真结果表明,基于Householder变换复数域格缩减的MIMO次优检测算法,通过优化信道矩阵可以得到更好的判决域,取得了逼近最优最大似然检测算法的性能。

关键词：检测 Householder 格缩减多入多出系统

退耕还林背景下寒地山区土地生态安全格局动态变化

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农业工程学报 2017年第18期33卷 267-276页

作者：侯大伟刘艳孙华南京农业大学土地管理学院南京210095

为了研究退耕还林工程引起的土地生态安全格局变化,该文应用遥感和GIS技术对牡丹江地区2000-2014年土地利用变化特征进行了分析,并基于DPSIR概念框架构建评价指标体系,从空间上揭示了研究区退耕还林期间土地生态安全水平及格局变化。结... 详细信息

为了研究退耕还林工程引起的土地生态安全格局变化,该文应用遥感和GIS技术对牡丹江地区2000-2014年土地利用变化特征进行了分析,并基于DPSIR概念框架构建评价指标体系,从空间上揭示了研究区退耕还林期间土地生态安全水平及格局变化。结果表明,退耕还林工程的实施对研究区土地利用结构产生了极大的影响,林地面积增加1 520.16 km^2,草地、耕地面积分别减少878.50、517.14 km^2,土地利用强度先下降后上升;退耕还林工程在有效控制坡地垦殖、增加林地面积的同时,能够显著提高区域土地生态安全水平,2000-2014年,各坡度等级内安全、较安全、临界安全面积共增加1 088.6 km^2;14 a来研究区土地生态安全水平总体呈"先改善后恶化"的趋势,但仍较2000年工程实施前有了较大幅度的提升,西部、东部及南部地区土地生态安全水平显著提高,但中部牡丹江河谷盆地土地生态安全水平提升缓慢,建议新一轮退耕还林工程将此地区作为重点调控整治区域。

关键词：土地利用生态植被退耕还林土地生态安全寒地山区

PRELIMINARY NOTE ON PRESENCE OF EARLY CARBONIFEROUS FLORULE FROM JILIN

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古生物学报 1987年第4期 464-469页

作者： Zhang Shan-zhen sun Ge and Zhao yan-hua

The purpose of the present paper is to recordthe discovery of Early Carboniferous plants of An-gara floral aspects from Jilin province,with spe-cial reference to its geological and phytogeographi-cal *** material was gathered by thegeologists of the Regional Geological Survey,Bure-au of Geology and Mineral Gesources,Jilin fromthe Lower Carboniferous Lujuantun Formation inPanshi District,Jilin Province（about 43°14′N *** 125°31′E Long.）(Text fig.l)during *** Lujuantun Formation,a set of darkgray to black,slightly metamorphic siltstone seriessome 500 m in thickness,is overlain by the UpperCarboniferous Mopanshan *** pub-lished is the stratigraphical sequence of a sectionof the Lujuantun Formation in descending orderfor *** Mopanshan Formation（C;m）

关键词： PRELIMINARY NOTE ON PRESENCE OF EARLY CARBONIFEROUS FLORULE FROM JILIN

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格缩减辅助MIMO检测的非线性量化

北京邮电大学学报 2010年第1期33卷 18-22页

作者：孙艳华王浩张延华北京工业大学电子信息与控制工程学院北京100124 普天信息技术研究院有限公司北京100080

针对格缩减辅助(LRA)多入多出(MIMO)检测中,采用格缩减技术后导致星座畸变、引起变换域信号非线性联合量化复杂度高的问题,提出了一种排序反馈的非线性量化算法.该算法同时考虑了变换星座的边界和各元素间的相关性,且根据量化误差的大... 详细信息

针对格缩减辅助(LRA)多入多出(MIMO)检测中,采用格缩减技术后导致星座畸变、引起变换域信号非线性联合量化复杂度高的问题,提出了一种排序反馈的非线性量化算法.该算法同时考虑了变换星座的边界和各元素间的相关性,且根据量化误差的大小选择信号量化判决的顺序,依次量化判决信号的各元素.仿真证明,基于该算法的格缩减辅助MIMO检测性能优于无排序反馈量化和逐元素独立量化的格缩减辅助MIMO检测,且能很好地逼近最大似然检测的性能;在平坦块衰落信道下,计算复杂度为多项式复杂度.

关键词：多入多出格缩减检测算法非线性量化

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探测激光入射角对猫眼效应反射特性的影响

强激光与粒子束 2007年第3期19卷 364-368页

作者：赵延仲孙华燕宋丰华装备指挥技术学院研究生院北京101416 装备指挥技术学院光电装备系北京101416

光电装备的光学窗口对入射激光有较强的反射特性,即猫眼效应现象。为了研究利用猫眼效应来进行主动探测的适用条件,弄清探测激光入射角对猫眼效应反射特性的影响,建立了斜入射猫眼效应反射模型,分析并仿真了探测激光在目标系统处的入射... 详细信息

光电装备的光学窗口对入射激光有较强的反射特性,即猫眼效应现象。为了研究利用猫眼效应来进行主动探测的适用条件,弄清探测激光入射角对猫眼效应反射特性的影响,建立了斜入射猫眼效应反射模型,分析并仿真了探测激光在目标系统处的入射角不同的情况下的后向反射激光特性,以及探测系统所能够接收的原路返回激光的远场能量分布情况。结果表明:对于特定的目标系统,猫眼效应现象只存在于一定的探测激光入射角范围之内,在此范围之内,猫眼效应反射特性与探测激光的入射角关系密切;基于猫眼效应的激光主动探测、定位等应用也是可行的。

关键词：主动探测反射特性猫眼效应入射角