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Comparison between ozonesonde measurements and satellite retrievals over Beijing,China 被引量:2
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作者 Jinqiang Zhang Yuejian Xuan +5 位作者 Jianchun Bian Holger Vomel Yunshu Zeng Zhixuan Bai Dan Li Hongbin Chen 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第1期14-20,共7页
从2013年开始,作者团队使用自主研发电化学原理臭氧探空仪在华北平原北京地区进行每周一次观测.本研究首次使用2013-2019年期间北京地区臭氧探空数据评估Aqua卫星搭载大气红外探测仪(AIRS)和Aura卫星搭载微波临边探测器(MLS)反演垂直臭... 从2013年开始,作者团队使用自主研发电化学原理臭氧探空仪在华北平原北京地区进行每周一次观测.本研究首次使用2013-2019年期间北京地区臭氧探空数据评估Aqua卫星搭载大气红外探测仪(AIRS)和Aura卫星搭载微波临边探测器(MLS)反演垂直臭氧廓线,并对比臭氧探空,AIRS和Aura卫星搭载臭氧监测仪(OMI)臭氧柱总量结果.尽管臭氧探空与卫星反演垂直臭氧廓线在局部高度处差异较大,但整体来说两者较为接近(相对偏差大多<10%).臭氧探空,AIRS和OMI三种仪器测量臭氧柱总量的年变化特征较为一致,其年均臭氧柱总量分别为351.8±18.4 DU,348.8±19.5 DU和336.9±14.2 DU.后续对国内多站点观测数据分析将有助于进一步理解臭氧探空与卫星反演臭氧资料在不同区域的一致性. 展开更多
关键词 臭氧探空 卫星反演 垂直臭氧廓线 臭氧柱总量 华北平原
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Joint Retrieval of PM_(2.5) Concentration and Aerosol Optical Depth over China Using Multi-Task Learning on FY-4A AGRI
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作者 Bo LI Disong FU +4 位作者 Ling YANG Xuehua FAN Dazhi YANG Hongrong SHI Xiang’ao XIA 《Advances in Atmospheric Sciences》 2025年第1期94-110,共17页
Aerosol optical depth(AOD)and fine particulate matter with a diameter of less than or equal to 2.5μm(PM_(2.5))play crucial roles in air quality,human health,and climate change.However,the complex correlation of AOD–... Aerosol optical depth(AOD)and fine particulate matter with a diameter of less than or equal to 2.5μm(PM_(2.5))play crucial roles in air quality,human health,and climate change.However,the complex correlation of AOD–PM_(2.5)and the limitations of existing algorithms pose a significant challenge in realizing the accurate joint retrieval of these two parameters at the same location.On this point,a multi-task learning(MTL)model,which enables the joint retrieval of PM_(2.5)concentration and AOD,is proposed and applied on the top-of-the-atmosphere reflectance data gathered by the Fengyun-4A Advanced Geosynchronous Radiation Imager(FY-4A AGRI),and compared to that of two single-task learning models—namely,Random Forest(RF)and Deep Neural Network(DNN).Specifically,MTL achieves a coefficient of determination(R^(2))of 0.88 and a root-mean-square error(RMSE)of 0.10 in AOD retrieval.In comparison to RF,the R^(2)increases by 0.04,the RMSE decreases by 0.02,and the percentage of retrieval results falling within the expected error range(Within-EE)rises by 5.55%.The R^(2)and RMSE of PM_(2.5)retrieval by MTL are 0.84 and 13.76μg m~(-3)respectively.Compared with RF,the R^(2)increases by 0.06,the RMSE decreases by 4.55μg m~(-3),and the Within-EE increases by 7.28%.Additionally,compared to DNN,MTL shows an increase of 0.01 in R^(2)and a decrease of 0.02 in RMSE in AOD retrieval,with a corresponding increase of 2.89%in Within-EE.For PM_(2.5)retrieval,MTL exhibits an increase of 0.05 in R^(2),a decrease of 1.76μg m~(-3)in RMSE,and an increase of 6.83%in Within-EE.The evaluation suggests that MTL is able to provide simultaneously improved AOD and PM_(2.5)retrievals,demonstrating a significant advantage in efficiently capturing the spatial distribution of PM_(2.5)concentration and AOD. 展开更多
关键词 AOD PM_(2.5) FY-4A multi-task learning joint retrieval
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Application of BP neural network model with fuzzy optimization in retrieval of biomass parameters 被引量:1
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作者 陈守煜 郭瑜 《Agricultural Science & Technology》 CAS 2005年第2期7-11,共5页
The retrieval of the biomass parameters from active/passive microwave remote sensing data (10.2 GHz) is performed based on an iterative inversion of BP neural network model with fuzzy optimization. The BP neural net... The retrieval of the biomass parameters from active/passive microwave remote sensing data (10.2 GHz) is performed based on an iterative inversion of BP neural network model with fuzzy optimization. The BP neural network is trained by a set of the measurements of active and passive remote sensing and the ground truth data versus Day of Year during growth. Once the network training is complete, the model can be used to retrieve the temporal variations of the biomass parameters from another set of observation data. The model was used in weights and microware observation data of wheat growth in 1989 to retrieve biomass parameters change of wheat growth this year. The retrieved biomass parameters correspond well with the real data of the growth, which shows that the BP model is scientific and sound. 展开更多
关键词 ANN BP model biomass parameters retrieval
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高校实验室PAR事故致因模型构建及应用
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作者 阳富强 黄宝娇 +1 位作者 葛樊亮 黄宗侯 《实验室研究与探索》 CAS 北大核心 2024年第7期249-253,共5页
高校实验室是集聚和培养优秀专业人才、开展高水平科学研究的重要基地,但目前仍面临较多安全管理难题。现以“中科院某研究所高压反应釜爆炸事故”为例,采用PAR事故致因模型开展高校实验室安全管理研究,以安全感知—安全分析—安全应答(... 高校实验室是集聚和培养优秀专业人才、开展高水平科学研究的重要基地,但目前仍面临较多安全管理难题。现以“中科院某研究所高压反应釜爆炸事故”为例,采用PAR事故致因模型开展高校实验室安全管理研究,以安全感知—安全分析—安全应答(PAR)为节点,对实验室建设与管理处、中心实验室、实验室操作主体3个层面进行分析。研究表明,PAR模型能充分发挥安全信息的交流作用,从宏观、中观、微观3个层面进行事故致因分析,为完善实验室事故分析体系等提供有效支撑。本研究对高校实验室安全管理的安全信息分析和风险防控提供参考,对实验室安全管理有一定理论指导意义。 展开更多
关键词 par事故致因模型 安全信息 高校实验室 安全管理
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基于PAR模型的我国煤矿安全脆弱性及其治理路径研究
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作者 赛明明 张雪君 《中国煤炭》 北大核心 2024年第12期59-70,共12页
基于PAR模型对我国煤矿安全脆弱性问题展开研究。在对近10年间70份煤矿事故调查报告进行文本编码的基础上,提取出影响煤矿安全脆弱性的关键因素,采用模糊层次分析法构建煤矿安全脆弱性影响因素指标体系,测算出各影响因素指标的权重数值... 基于PAR模型对我国煤矿安全脆弱性问题展开研究。在对近10年间70份煤矿事故调查报告进行文本编码的基础上,提取出影响煤矿安全脆弱性的关键因素,采用模糊层次分析法构建煤矿安全脆弱性影响因素指标体系,测算出各影响因素指标的权重数值,判断其对煤矿安全的相对重要程度。结果表明,“政府治理能力”“企业管理能力”“外在环境条件”是影响煤矿安全脆弱性的三大核心要素;需重点通过深化政府安全意识、完善应急管理体系、优化政府监管能力、强化企业制度执行、加强矿区应急联动、拓展提升员工素质等措施来最大程度地降低煤矿安全脆弱性. 展开更多
关键词 煤矿安全 脆弱性 治理路径 par模型
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Comparison of sperm retrieval and reproductive outcome in azoospermic men with testicular failure and obstructive azoospermia treated for infertility 被引量:10
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作者 Sandro C Esteves Christina Prudencio +3 位作者 Bill Seol Sidney Verza jr Christopher Knoedler Ashok Agarwal 《Asian Journal of Andrology》 SCIE CAS CSCD 2014年第4期602-606,共5页
We assessed the rates of sperm retrieval and intracytoplasmic sperm injection outcomes, including the neonatal profile of infants conceived, in men with testicular failure. Three-hundred and sixty-five men with testic... We assessed the rates of sperm retrieval and intracytoplasmic sperm injection outcomes, including the neonatal profile of infants conceived, in men with testicular failure. Three-hundred and sixty-five men with testicular failure who underwent micro-dissection testicular sperm extraction were included in this study. We compared their outcomes with 40 men with testicular failure who used donor sperm for injections due to failed retrieval, and 146 men with obstructive azoospermia who underwent percutaneous sperm retrieval. The retrieval rate in testicular failure was 41.4%, and the results were lower than the obstructed azoospermia (100%; adjusted odds ratio: 0.033; 95% Ch 0.007-0.164; P 〈 0.001). Live birth rates after sperm injections were lower in men with testicular failure (19.9%) compared with donor sperm (37.5%; adjusted OR: 0.377 (95% Ch 0.233-0.609, P 〈 0.001)) and obstructive azoospermia (34.2%; adjusted OR: 0.403 (95% CI: 0.241-0.676, P= 0.001). Newborn parameters of infants conceived were not significantly different among the groups. We concluded that the chances of obtaining sperm on retrieval and achieving a live birth after intracytoplasmic sperm injection (ICSI) are reduced in men with testicular failure. The profile of infants conceived after sperm injection does not seem to be negatively affected by testicular failure. 展开更多
关键词 INFANT intracytoplasmic sperm injection obstructive azoospermia pregnancy outcome sperm retrieval testicular failure
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Retrieval of Atmospheric and Oceanic Parameters and the Relevant Numerical Calculation 被引量:2
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作者 黄思训 曹小群 +2 位作者 杜华栋 王廷芳 项杰 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2006年第1期106-117,共12页
It is well known that retrieval of parameters is usually ill-posed and highly nonlinear, so parameter retrieval problems are very difficult. There are still many important theoretical issues under research, although g... It is well known that retrieval of parameters is usually ill-posed and highly nonlinear, so parameter retrieval problems are very difficult. There are still many important theoretical issues under research, although great success has been achieved in data assimilation in meteorology and oceanography. This paper reviews the recent research on parameter retrieval, especially that of the authors. First, some concepts and issues of parameter retrieval are introduced and the state-of-the-art parameter retrieval technology in meteorology and oceanography is reviewed briefly, and then atmospheric and oceanic parameters are retrieved using the variational data assimilation method combined with the regularization techniques in four examples: retrieval of the vertical eddy diffusion coefficient; of the turbulivity of the atmospheric boundary layer; of wind from Doppler radar data, and of the physical process parameters. Model parameter retrieval with global and local observations is also introduced. 展开更多
关键词 variational data assimilation parameter retrieval ill-posed problem REGULARIZATION
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A COMPARISON OF THE RETRIEVAL OF ATMOSPHERIC TEMPERATURE PROFILES USING OBSERVATIONS OF THE 60 GHZ AND 118.75 GHZ ABSORPTION LINES 被引量:2
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作者 HE Qiu-rui WANG Zhen-zhan +1 位作者 HE Jie-ying ZHANG Lan-jie 《Journal of Tropical Meteorology》 SCIE 2018年第2期151-162,共12页
The Microwave Temperature Sounder-Ⅱ(MWTS-Ⅱ) and Microwave Humidity and Temperature Sounder(MWHTS) onboard the Fengyun-3 C(FY-3 C) satellite can be used to detect atmospheric temperature profiles. The MWTS-II has 13 ... The Microwave Temperature Sounder-Ⅱ(MWTS-Ⅱ) and Microwave Humidity and Temperature Sounder(MWHTS) onboard the Fengyun-3 C(FY-3 C) satellite can be used to detect atmospheric temperature profiles. The MWTS-II has 13 temperature sounding channels around the 60 GHz oxygen absorption band and the MWHTS has 8 temperature sounding channels around the 118.75 GHz oxygen absorption line. The data quality of the observed brightness temperatures can be evaluated using atmospheric temperature retrievals from the MWTS-Ⅱ and MWHTS observations. Here, the bias characteristics and corrections of the observed brightness temperatures are described. The information contents of observations are calculated, and the retrieved atmospheric temperature profiles are compared using a neural network(NN) retrieval algorithm and a one-dimensional variational inversion(1 D-var) retrieval algorithm. The retrieval results from the NN algorithm show that the accuracy of the MWTS-Ⅱ retrieval is higher than that of the MWHTS retrieval, which is consistent with the results of the radiometric information analysis. The retrieval results from the 1 D-var algorithm show that the accuracy of MWTS-Ⅱ retrieval is similar to that of the MWHTS retrieval at the levels from 850-1,000 h Pa, is lower than that of the MWHTS retrieval at the levels from 650-850 h Pa and 125-300 h Pa, and is higher than that of MWHTS at the other levels. A comparison of the retrieved atmospheric temperature using these satellite observations provides a reference value for assessing the accuracy of atmospheric temperature detection at the 60 GHz oxygen band and 118.75 GHz oxygen line. In addition, based on the comparison of the retrieval results, an optimized combination method is proposed using a branch and bound algorithm for the NN retrieval algorithm, which combines the observations from both the MWTS-Ⅱand MWHTS instruments to retrieve the atmospheric temperature profiles. The results show that the optimal combination can further improve the accuracy of MWTS-Ⅱ retrieval and enhance the detection accuracy of atmospheric temperatures near the surface. 展开更多
关键词 Fengyun-3C satellite Microwave Temperature Sounder-II microwave humidity and temperature sounder one-dimensional variational retrieval algorithm neural networks retrieval algorithm
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Study of the Simultaneous Physical Retrieval Method for Meteorological Parameters over the Continental Plateau of China 被引量:2
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作者 黎光清 董超华 +3 位作者 张文建 吴保锁 王维和 吴治电 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1994年第3期296-310,共15页
It is common knowledge that continental retrieval especially for Qinghai-Xizang Plateau has not been solved todate. In order to explore applicable inverse model and method for continent including the plateau, in this ... It is common knowledge that continental retrieval especially for Qinghai-Xizang Plateau has not been solved todate. In order to explore applicable inverse model and method for continent including the plateau, in this study authors use an improved simultaneous physical retrieval method hereafter referred to as the ISPRM, for computing meteorological parameters from NOAA-10 satellite TOVS data. The retrieval results verified by nearby radiosondesshow that the ISPRM is more applicable for the continental plateau. 展开更多
关键词 retrieval method Optimum first guess Self-consistence Forward Computation Ground truth verification
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Fourier Descriptors with Different Shape Signatures:a Comparative Study for Shape Based Retrieval of Kinematic Constraints 被引量:1
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作者 WU Jun GE Qiaode Jeffrey +1 位作者 GAO Feng SU Haijun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第5期723-730,共8页
Fourier Descriptors(FD) has been widely used in image analysis and computer vision for shape recognition as they can be made independent of translation,rotation,as well as scaling.They have also been used for develo... Fourier Descriptors(FD) has been widely used in image analysis and computer vision for shape recognition as they can be made independent of translation,rotation,as well as scaling.They have also been used for developing methods for the analysis and synthesis of four-bar linkages for path generation.This paper focuses on a comparative study of Fourier descriptors derived from various shape signatures of planar closed curves.This includes representations based on Cartesian coordinates,centroid distance,cumulative angle,and curvature.The comparison is conducted not only using commonly used criteria for shape representation and identification but also in the context of shape based retrieval of kinematic constraints for task centered mechanism design.Examples are provided to seek to extract geometric constraints such as circle,circular arc,ellipse and line-segment from a given motion. 展开更多
关键词 Fourier descriptors kinematic constraints shape recognition and retrieval
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Ground-based/UAV-LiDAR data fusion for quantitative structure modeling and tree parameter retrieval in subtropical planted forest 被引量:5
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作者 Reda Fekry Wei Yao +1 位作者 Lin Cao Xin Shen 《Forest Ecosystems》 SCIE CSCD 2022年第5期674-691,共18页
Light detection and ranging(LiDAR)has contributed immensely to forest mapping and 3D tree modelling.From the perspective of data acquisition,the integration of LiDAR data from different platforms would enrich forest i... Light detection and ranging(LiDAR)has contributed immensely to forest mapping and 3D tree modelling.From the perspective of data acquisition,the integration of LiDAR data from different platforms would enrich forest information at the tree and plot levels.This research develops a general framework to integrate ground-based and UAV-LiDAR(ULS)data to better estimate tree parameters based on quantitative structure modelling(QSM).This is accomplished in three sequential steps.First,the ground-based/ULS LiDAR data were co-registered based on the local density peaks of the clustered canopy.Next,redundancy and noise were removed for the ground-based/ULS LiDAR data fusion.Finally,tree modeling and biophysical parameter retrieval were based on QSM.Experiments were performed for Backpack/Handheld/UAV-based multi-platform mobile LiDAR data of a subtropical forest,including poplar and dawn redwood species.Generally,ground-based/ULS LiDAR data fusion outperforms ground-based LiDAR with respect to tree parameter estimation compared to field data.The fusion-derived tree height,tree volume,and crown volume significantly improved by up to 9.01%,5.28%,and 18.61%,respectively,in terms of rRMSE.By contrast,the diameter at breast height(DBH)is the parameter that has the least benefits from fusion,and rRMSE remains approximately the same,because stems are already well sampled from ground data.Additionally,particularly for dense forests,the fusion-derived tree parameters were improved compared to those derived from ground-based LiDAR.Ground-based LiDAR can potentially be used to estimate tree parameters in low-stand-density forests,whereby the improvement owing to fusion is not significant. 展开更多
关键词 Ground/aerial view mobile LiDAR Point cloud CO-REGISTRATION FUSION QSM Tree parameter retrieval
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A Content-Based Parallel Image Retrieval System on Cluster Architectures 被引量:1
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作者 ZHOUBing SHENJun-yi PENGQin-ke 《Wuhan University Journal of Natural Sciences》 CAS 2004年第5期665-670,共6页
We propose a content-based parallel image retrieval system to achieve high responding ability. Our system is developed on cluster architectures. It has several retrieval. servers to supply the service of content-based... We propose a content-based parallel image retrieval system to achieve high responding ability. Our system is developed on cluster architectures. It has several retrieval. servers to supply the service of content-based image retrieval. It adopts the Browser/Server (B/S) mode. The users could visit our system though web pages. It uses the symmetrical color-spatial features (SCSF) to represent the content of an image. The SCSF is effective and efficient for image matching because it is independent of image distortion such as rotation and flip as well as it increases the matching accuracy. The SCSF was organized by M-tree, which could speedup the searching procedure. Our experiments show that the image matching is quickly and efficiently with the use of SCSF. And with the support of several retrieval servers, the system could respond to many users at mean time. Key words content-based image retrieval - cluster architecture - color-spatial feature - B/S mode - task parallel - WWW - Internet CLC number TP391 Foundation item: Supported by the National Natural Science Foundation of China (60173058)Biography: ZHOU Bing (1975-), male, Ph. D candidate, reseach direction: data mining, content-based image retrieval. 展开更多
关键词 content-based image retrieval cluster architecture color-spatial feature B/S mode task parallel WWW INTERNET
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Multi-core based parallel computing technique for content-based image retrieval 被引量:1
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作者 陈文浩 方昱春 +1 位作者 姚继锋 张武 《Journal of Shanghai University(English Edition)》 2010年第1期55-59,共5页
In this paper, we propose a parallel computing technique for content-based image retrieval (CBIR) system. This technique is mainly used for single node with multi-core processor, which is different from those based ... In this paper, we propose a parallel computing technique for content-based image retrieval (CBIR) system. This technique is mainly used for single node with multi-core processor, which is different from those based on cluster or network computing architecture. Due to its specific applications (such as medical image processing) and the harsh terms of hardware resource requirement, the CBIR system has been prevented from being widely used. With the increasing volume of the image database, the widespread use of multi-core processors, and the requirement of the retrieval accuracy and speed, we need to achieve a retrieval strategy which is based on multi-core processor to make the retrieval faster and more convenient than before. Experimental results demonstrate that this parallel architecture can significantly improve the performance of retrieval system. In addition, we also propose an efficient parallel technique with the combinations of the cluster and the multi-core techniques, which is supposed to gear to the new trend of the cloud computing. 展开更多
关键词 content-based image retrieval (CBIR) parallel computing SHARED-MEMORY feature extraction similarity comparison
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RESEARCH ON OPTIMIZING THE MERGING RESULTS OF MULTIPLE INDEPENDENT RETRIEVAL SYSTEMS BY A DISCRETE PARTICLE SWARM OPTIMIZATION 被引量:1
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作者 XieXingsheng ZhangGuoliang XiongYan 《Journal of Electronics(China)》 2012年第1期111-119,共9页
The result merging for multiple Independent Resource Retrieval Systems (IRRSs), which is a key component in developing a meta-search engine, is a difficult problem that still not effectively solved. Most of the existi... The result merging for multiple Independent Resource Retrieval Systems (IRRSs), which is a key component in developing a meta-search engine, is a difficult problem that still not effectively solved. Most of the existing result merging methods, usually suffered a great influence from the usefulness weight of different IRRS results and overlap rate among them. In this paper, we proposed a scheme that being capable of coalescing and optimizing a group of existing multi-sources-retrieval merging results effectively by Discrete Particle Swarm Optimization (DPSO). The experimental results show that the DPSO, not only can overall outperform all the other result merging algorithms it employed, but also has better adaptability in application for unnecessarily taking into account different IRRS's usefulness weight and their overlap rate with respect to a concrete query. Compared to other result merging algorithms it employed, the DPSO's recognition precision can increase nearly 24.6%, while the precision standard deviation for different queries can decrease about 68.3%. 展开更多
关键词 Multiple resource retrievals Result merging Meta-search engine Discrete particleSwarm Optimization (DPSO)
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Chaos Particle Swarm Optimization Combined with Circular Median Filtering for Geophysical Parameters Retrieval from WindSat 被引量:2
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作者 ZHANG Lei WANG Zhenzhan +2 位作者 SHI Hanqing LONG Zhiyong DU Huadong 《Journal of Ocean University of China》 SCIE CAS 2016年第4期593-605,共13页
This paper established a geophysical retrieval algorithm for sea surface wind vector, sea surface temperature, columnar atmospheric water vapor, and columnar cloud liquid water from WindSat, using the measured brightn... This paper established a geophysical retrieval algorithm for sea surface wind vector, sea surface temperature, columnar atmospheric water vapor, and columnar cloud liquid water from WindSat, using the measured brightness temperatures and a matchup database. To retrieve the wind vector, a chaotic particle swarm approach was used to determine a set of possible wind vector solutions which minimize the difference between the forward model and the WindSat observations. An adjusted circular median filtering function was adopted to remove wind direction ambiguity. The validation of the wind speed, wind direction, sea surface temperature, columnar atmospheric water vapor, and columnar liquid cloud water indicates that this algorithm is feasible and reasonable and can be used to retrieve these atmospheric and oceanic parameters. Compared with moored buoy data, the RMS errors for wind speed and sea surface temperature were 0.92 m s^(-1) and 0.88℃, respectively. The RMS errors for columnar atmospheric water vapor and columnar liquid cloud water were 0.62 mm and 0.01 mm, respectively, compared with F17 SSMIS results. In addition, monthly average results indicated that these parameters are in good agreement with AMSR-E results. Wind direction retrieval was studied under various wind speed conditions and validated by comparing to the Quik SCAT measurements, and the RMS error was 13.3?. This paper offers a new approach to the study of ocean wind vector retrieval using a polarimetric microwave radiometer. 展开更多
关键词 retrieval retrieval cloud Chaos columnar geophysical brightness retrieve validated swarm
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Turbulence and Rainfall Microphysical Parameters Retrieval and Their Relationship Analysis Based on Wind Profiler Radar Data 被引量:1
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作者 HU Su-man HUANG Xing-you MA Yu-rong 《Journal of Tropical Meteorology》 SCIE 2021年第3期291-302,共12页
Rainfall is triggered and mainly dominated by atmospheric thermo-dynamics and rich water vapor.Nonetheless, turbulence is also considered as an important factor influencing the evolution of rainfall microphysical para... Rainfall is triggered and mainly dominated by atmospheric thermo-dynamics and rich water vapor.Nonetheless, turbulence is also considered as an important factor influencing the evolution of rainfall microphysical parameters. To study such an influence, the present study utilized boundary layer wind profiler radar measurements. The separation point of the radar power spectral density data was carefully selected to classify rainfall and turbulence signals;the turbulent dissipation rate ε and rainfall microphysical parameters can be retrieved to analyze the relationship betweenε and microphysical parameters. According to the retrievals of two rainfall periods in Beijing 2016, it was observed that(1) ε in the precipitation area ranged from 10^(-3.5) to 10^(-1) m^(2) s^(-3) and was positively correlated with the falling velocity spectrum width;(2) interactions between turbulence and raindrops showed that small raindrops got enlarge through collision and coalescence in weak turbulence, but large raindrops broke up into small drops under strong turbulence, and the separation value of ε being weak or strong varied with rainfall attributes;(3) the variation of rainfall microphysical parameters(characteristic diameters, number concentration, rainfall intensity, and water content) in the middle stage were stronger than those in the early and the later stages of rainfall event;(4) unlike the obvious impacts on raindrop size and number concentration, turbulence impacts on rain rate and LWC were not significant because turbulence did not cause too much water vapor and heat exchange. 展开更多
关键词 turbulent dissipation rate rainfall microphysical parameters wind profiler radar spectrum width collision-coalescence BREAKUP retrieval
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Case Retrieval Method of Multi-parameter for Customized Product
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作者 DING Junjian TAN Shili SONG Xiaofeng WANG Meiting (School of Mechanical&Electronic Engineering and Automation,Shanghai University,Shanghai 200072,China 《武汉理工大学学报》 CAS CSCD 北大核心 2006年第S2期543-546,共4页
The CBR (Case-Based Reasoning) usually is been used to accomplish customized products by variant design or reusable design.In the CBR,retrieve is very important.A simple case retrieval method is been brought forward t... The CBR (Case-Based Reasoning) usually is been used to accomplish customized products by variant design or reusable design.In the CBR,retrieve is very important.A simple case retrieval method is been brought forward to retrieve a opti- mal prototype based on using inputted multi-parameters,it can be programmed easily.An example has been proved this method can find optimal prototype for new design task efficiently. 展开更多
关键词 case-based REASONING retrieve similar DISTANCE MULTI-parAMETER
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PARP-1在染料木素作用小鼠卵泡发生进程中的表达特征
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作者 郭卓倩 王金 +5 位作者 卢凤兰 苟廷廷 孟秋仙 尧燕环 吴华东 吴国云 《江西农业大学学报》 CAS CSCD 北大核心 2024年第2期438-446,共9页
【目的】旨在探究PARP-1信号及其介导的PAR化修饰水平在染料木素促进卵泡发育和抑制卵泡闭锁进程中的相关性,丰富染料木素等类雌激素物质作用于雌性哺乳动物卵巢卵泡发生的作用机制,以期为种畜高产日粮配方的研制提供科学指导。【方法】... 【目的】旨在探究PARP-1信号及其介导的PAR化修饰水平在染料木素促进卵泡发育和抑制卵泡闭锁进程中的相关性,丰富染料木素等类雌激素物质作用于雌性哺乳动物卵巢卵泡发生的作用机制,以期为种畜高产日粮配方的研制提供科学指导。【方法】以21 d雌性昆明小鼠为试验动物,采用腹腔注射25,50,100 mg/kg不同剂量染料木素,每日定点注射1次,连续7 d,采集卵巢组织和血清,采用免疫组织化学法检测PARP-1蛋白在卵巢组织内的表达特征,并运用Western blot对卵巢组织内PARP-1蛋白及pADPr进行定量。结合凋亡指示蛋白Cleaved-caspase3、雌二醇(E2)水平、类固醇合成酶CYP19A1和HSD17B1,综合分析PARP-1信号及其介导的PAR化修饰信号是如何参与染料木素抑制卵泡闭锁、促进卵泡发育进程。【结果】免疫组织化学染色显示,PARP-1阳染主要发生在原始卵泡、初级卵泡、次级卵泡、有腔卵泡中的健康颗粒细胞核和卵母细胞,卵泡膜细胞次之,但在Cleaved-caspase3阳染的凋亡细胞中PARP-1不表达。Western blot结果显示,50 mg/kg染料木素处理组PARP-1解离片段(89 ku)的表达量较对照组显著降低(P<0.05),但PARP-1全段(116 ku)表达量在各剂量组无显著差异(P>0.05)。其次,50 mg/kg染料木素处理组的pADPr的表达量在15 ku以下、25 ku以及35~45 ku这3个区域内均显著低于对照组、25 mg/kg和100 mg/kg剂量组(P<0.05),100 mg/kg剂量组的pADPr仅在25 ku区域处表达量较对照组和25 mg/kg剂量组显著降低(P<0.05)。然而,较对照组,Cleaved-caspase3的表达量在25 mg/kg和50 mg/kg染料木素处理组呈现剂量依赖性下降,且在50 mg/kg剂量组差异显著(P<0.05);E2水平较对照组亦呈现剂量依赖性上升且差异显著(P<0.05),但雌激素合成酶CYP19A1和HSD17B1的表达无显著变化(P>0.05)。【结论】PARP-1广泛存在于哺乳动物卵巢内健康的颗粒细胞、卵泡细胞和膜细胞中,可能通过催化pADPr的合成,介导卵巢内的能量代谢、细胞凋亡以及类固醇激素合成等胞内活动,参与染料木素等类雌激素物质干扰卵巢卵泡发生进程。 展开更多
关键词 小鼠 染料木素 卵泡发生 parP-1 par
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Laparoscopic retrieval of two intragastric spoons at least seven years after ingestion 被引量:1
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作者 Adeel Ahmed Shamim Muhammad Maaz Zuberi Amir Hafeez Shariff 《Laparoscopic, Endoscopic and Robotic Surgery》 2019年第3期77-79,共3页
Foreign body ingestion is a commonly encountered presentation.The majority of foreign bodies pass in stool spontaneously within one week or are managed endoscopically within the first 24e48 hours.No guidelines are ava... Foreign body ingestion is a commonly encountered presentation.The majority of foreign bodies pass in stool spontaneously within one week or are managed endoscopically within the first 24e48 hours.No guidelines are available for management of chronically retained foreign bodies at present.A unique case is presented of two chronically retained teaspoons in the stomach that failed endoscopic retrieval and required laparoscopic surgery.Post operatively,the patient did well with no complications.A large foreign body that is not amenable to endoscopic intervention will benefit from surgery.If expertise is available,laparoscopic intervention is a safe and feasible option to remove large foreign bodies from the stomach that is not amenable to endoscopic retrieval. 展开更多
关键词 ENDOSCOPY Large foreign body ingestion Laparoscopic retrieval
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Spectrum Feature Retrieval and Comparison of Remote Sensing Images Using Improved ISODATA Algorithm
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作者 刘磊 敬忠良 肖刚 《Journal of Shanghai Jiaotong university(Science)》 EI 2004年第3期60-64,79,共6页
Due to the large quantities of data and high relativity of the spectra of remote sensing images, K-L transformation is used to eliminate the relativity. An improved ISODATA(Interative Self-Organizing Data Analysis Tec... Due to the large quantities of data and high relativity of the spectra of remote sensing images, K-L transformation is used to eliminate the relativity. An improved ISODATA(Interative Self-Organizing Data Analysis Technique A) algorithm is used to extract the spectrum features of the images. The computation is greatly reduced and the dynamic arguments are realized. The comparison of features between two images is carried out, and good results are achieved in simulation. 展开更多
关键词 remote sensing image spectrum feature retrieval ISODATA
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