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基于量子滤光及跟踪算法的火箭发动机尾焰粒子测速方法研究
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作者 郭宸 常胜利 +3 位作者 张文杰 肖广益 王飞 鲍桐 《光学精密工程》 EI CAS CSCD 北大核心 2023年第16期2352-2361,共10页
粒子喷射速度的测速是火箭发动机结构改进设计极其重要的依据。但是由于火箭发动机尾焰喷射速度快、背景辐射强,传统的滤光器件(滤光片)与运动目标检测算法无法适用。针对上述问题,本文采取新型量子滤光技术,利用量子高信噪比,低背景噪... 粒子喷射速度的测速是火箭发动机结构改进设计极其重要的依据。但是由于火箭发动机尾焰喷射速度快、背景辐射强,传统的滤光器件(滤光片)与运动目标检测算法无法适用。针对上述问题,本文采取新型量子滤光技术,利用量子高信噪比,低背景噪声的特点,以原子滤光器为核心,将超窄带量子滤光技术应用到粒子图像测速法(Particle Image Ve⁃locimetry,PIV)中,组成量子滤光PIV系统,滤光带宽可窄至GHz量级。同时基于量子滤光PIV系统提出了一种新的基于图像灰度互相关的虚拟粒子图像示踪算法,该算法通过对虚拟粒子的标记跟踪而表征实际粒子的运动轨迹,达到测量粒子速度的目的。经外场试验表明:量子滤光技术抑制复杂背景干扰强,相较于传统滤光器件信噪比提高了30 dB,滤光效果明显;该算法准确性高,粒子测速误差低于0.5 m/s,计算测量精度优于0.06%。同时,相关系统已经在国家相关研究单位获得应用。 展开更多
关键词 火箭发动机 粒子喷射速度 量子滤光 示踪算法 信噪比 测量精度
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Using ^(137)Cs Tracing Methods to Estimate Soil Redistribution Rates and to Construct a Sediment Budget for a Small Agricultural Catchment in the Three Gorges Reservoir Region,China 被引量:7
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作者 JU Li WEN An-bang +2 位作者 LONG Yi YAN Dong-chun GUO Jin 《Journal of Mountain Science》 SCIE CSCD 2013年第3期428-436,共9页
Soil erosion and associated off-site sedimentation are threatening the sustainable use of the Three Gorges Dam. To initiate management intervention to reduce sediment yields, there is an increasing need for reliable i... Soil erosion and associated off-site sedimentation are threatening the sustainable use of the Three Gorges Dam. To initiate management intervention to reduce sediment yields, there is an increasing need for reliable information on soil erosion in the Three Gorges Reservoir Region (TGRR). The purpose of this study is to use 137Cs tracing methods to construct a sediment budget for a small agricultural catchment in the TGRR. Cores were taken from a pond and from paddy fields, for laTCs measurements. The results show that the average sedimentation rate in the pond since 1963 is 1.50 g cm-2 yr-1 and the corresponding amount of sediment deposited is 1,553 t. The surface erosion rate for the sloping cultivated lands and the sedimentation rate in the paddy fields were estimated to be 3,770 t km-2 yr-1 and 2,600 t km-2 yr^1 respectively. Based on the estimated erosion and deposition rates, and the area of each unit, the post 197o sediment budget for the catchment has been constructed. A sediment delivery ratio of 0.5 has been estimated for the past 42 years. The data indicate that the sloping cultivated lands are the primary sediment source areas, and that the paddy fields are deposition zones. The typical land use pattern (with the upper parts characterized by sloping cultivated land and the lower parts by paddy fields) plays an important role in reducing sediment yield from agricultural catchments in the TGRR. A 137Cs profile for the sediment deposited in a pond is shownto provide an effective means of estimating the land surface erosion rate in the upstream catchment. 展开更多
关键词 Pond deposition Soil erosion rate Sediment budget 137Cs Sediment delivery ratio Three Gorges Reservoir Region
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Probabilistic Tracking of Objects with Adaptive Cue Fusion Mechanism 被引量:1
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作者 张波 田蔚风 金志华 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第2期185-189,共5页
A tracking method based on adaptive multiple cue fusion mechanism was presented,where particle filter is used to integrate color and edge cues.The fusion mechanism assigns different weights to two cues according to th... A tracking method based on adaptive multiple cue fusion mechanism was presented,where particle filter is used to integrate color and edge cues.The fusion mechanism assigns different weights to two cues according to their importance,thus improving the robustness and reliability of the tracking algorithm.Moreover,a multi-part color model is also invoked to deal with the confliction among similar objects.The experimental results on two real image sequences show the tracking algorithm with adaptive fusion mechanism performs well in the presence of complex scenarios such as head rotation,scale change and multiple person occlusions. 展开更多
关键词 multiple cue fusion particle filter multi-part color model
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