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Quantitative Evaluation of Leaf Inclination Angle Distribution on Leaf Area Index Retrieval of Coniferous Canopies

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Journal of Remote Sensing 2021年第1期2021卷 1-15页

作者： guangjian Yan Hailan Jiang Jinghui Luo Xihan Mu Fan Li Jianbo Qi Ronghai Hu Donghui Xie Guoqing Zhou State Key Laboratory of Remote Sensing Science Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Southwest China Research Institute of Electronic Equipment Chengdu 610036China Guilin University of Technology Guilin 532100China

Both leaf inclination angle distribution(LAD)and leaf area index(LAI)dominate optical remote sensing *** G-function,which is a function of LAD and remote sensing geometry,is often set to 0.5 in the LAI retrieval of coniferous canopies even though this assumption is only valid for spherical *** uncertainties are thus ***,because numerous tiny leaves grow on conifers,it is nearly impossible to quantitatively evaluate such uncertainties in LAI *** this study,we proposed a method to characterize the possible change of G-function of coniferous canopies as well as its effect on LAI ***,a Multi-Directional Imager(MDI)was developed to capture stereo images of the branches,and the needles were *** accuracy of the inclination angles calculated from the reconstructed needles was ***,we analyzed whether a spherical distribution is a valid assumption for coniferous canopies by calculating the possible range of the G-function from the measured LADs of branches of Larch and Spruce and the true G-functions of other species from some existing inventory data and threedimensional(3D)tree *** show that the constant G assumption introduces large errors in LAI retrieval,which could be as large as 53%in the zenithal viewing direction used by spaceborne *** a result,accurate LAD estimation is *** the absence of such data,our results show that a viewing zenith angle between 45 and 65 degrees is a good choice,at which the errors of LAI retrieval caused by the spherical assumption will be less than 10%for coniferous canopies.

关键词： distribution function viewing

Progress in computational intelligence analysis

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Journal of Library Science in China 2019年 163-164页

作者： LI guangjian LUO Liqun 不详

In the 21st century,with the wide application of network technology and the rise of big data ideas and methods,intelligence analysis has gradually evolved from simple quantitative analysis to computational analysis in theory and *** intelligence analysis(CIA)is gradually taking *** development process of CIA can be divided into three stages:the empirical counting analysis stage.

关键词： Progress analysis intelligence

Industrial-Scale Polypropylene–Polyethylene Physical Alloying Toward Recycling

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Engineering 2022年第2期8卷 95-100页

作者： Jinping Qu Zhaoxia Huang Zhitao Yang Guizhen Zhang Xiaochun Yin Yanhong Feng Hezhi He Gang Jin Ting Wu guangjian He Xianwu Cao National Engineering Research Center of Novel Equipment for Polymer Processing&Key Laboratory of Polymer Processing Engineering of the Ministry of Education&Guangdong Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510640China

Polypropylene(PP)and polyethylene(PE)play central roles in our daily ***,their immiscibility presents a major hurdle in both industry and academia when recycling them into alloys with favorable mechanical ***,typical compatibilizer-enabled approaches are limited due to increased environmental ***,inspired by a traditional Chinese technique,we report a facile,industry-scale methodology that produces a PP/PE binary blend with a highly ordered honeycomb nanostructure without any *** to its nanostructure,the blend exhibits enhanced tensile properties in com-parison with the parent components or with a sample prepared using an internal *** approach has potential for applications not only in immiscible polymer blending,but also in non-sorting,compatibilizer-free waste plastics *** this technique,we expect that an environmentally friendly and sustainable plastic wastes recycling avenue can be found,and great economic benefits can be gained.

关键词： Polypropylene Polyethylene Physical alloying Honeycomb structure

High Spatial Resolution and High Temporal Frequency(30-m/15-day) Fractional Vegetation Cover Estimation over China Using Multiple Remote Sensing Datasets:Method Development and Validation

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Journal of Meteorological Research 2021年第1期35卷 128-147页

作者： Xihan MU Tian ZHAO Gaiyan RUAN Jinling SONG Jindi WANG guangjian YAN Tim RMCVICAR Kai YAN Zhan GAO Yaokai LIU Yuanyuan WANG State Key Laboratory of Remote Sensing Science Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Beijing Engineering Research Center for Global Land Remote Sensing Products Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China CSIRO Land and Water ACT2601Australia Department of Earth and Environment Boston UniversityBostonMA 02215USA Jiangsu Institute of Urban Planning and Design Nanjing 210036China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China National Satellite Meteorological Center China Meteorological AdministrationBeijing 100081China

High spatial resolution and high temporal frequency fractional vegetation cover(FVC) products have been increasingly in demand to monitor and research land surface processes. This paper develops an algorithm to estimate FVC at a 30-m/15-day resolution over China by taking advantage of the spatial and temporal information from different types of sensors: the 30-m resolution sensor on the Chinese environment satellite(HJ-1) and the 1-km Moderate Resolution Imaging Spectroradiometer(MODIS). The algorithm was implemented for each main vegetation class and each land cover type over China. First, the high spatial resolution and high temporal frequency normalized difference vegetation index(NDVI) was acquired by using the continuous correction(CC) data assimilation method. Then, FVC was generated with a nonlinear pixel unmixing model. Model coefficients were obtained by statistical analysis of the MODIS NDVI. The proposed method was evaluated based on in situ FVC measurements and a global FVC product(GEOV1 FVC). Direct validation using in situ measurements at 97 sampling plots per half month in 2010 showed that the annual mean errors(MEs) of forest, cropland, and grassland were-0.025, 0.133, and 0.160, respectively, indicating that the FVCs derived from the proposed algorithm were consistent with ground measurements [R2 = 0.809,root-mean-square deviation(RMSD) = 0.065]. An intercomparison between the proposed FVC and GEOV1 FVC demonstrated that the two products had good spatial–temporal consistency and similar magnitude(RMSD approximates 0.1). Overall, the approach provides a new operational way to estimate high spatial resolution and high temporal frequency FVC from multiple remote sensing datasets.

关键词： fractional vegetation cover(FVC) high spatial resolution and high temporal frequency data fusion normalized difference vegetation index(NDVI) pixel unmixing model multiple remote sensing datasets

Characterization of individual fly ash particles in surface snow at Urumqi Glacier No. 1, Eastern Tianshan

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Chinese Science Bulletin 2011年第34期56卷 3464-3473页

作者： ZHANG XueLei WU guangjian YAO TanDong ZHANG ChengLong YUE YaHui Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China＂ State Key Laboratory of Cryospheric Science Chinese Academy of Sciences Lanzhou 730000 China Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

This research aimed to identify and characterize individual spherical fly ash particles extracted from surface snow at Urumqi Glacier No.1 (UG1), Eastern Tien Shan, central Asia. Characterization of the spherical particles (i.e. morphology, chemical composition and genesis) was obtained by scanning electron microscopy coupled with energy dispersive X-ray spectrometer (SEM-EDX). This method enabled the characterization of submicroscopic spherical particles, which were present in very small quantities. Spherical particles and agglomerates were identified according to their morphology in five snow samples. Prevalent particle types in all samples were granular spherical particles, hollow spherical particles, irregularly shaped carbonaceous particles and agglomerates. The vast majority of spherical particles in our samples had mostly smooth and glossy surfaces, although these particles varied in diameter and elemental composition. The diameter of fly ash particles ranged from 0.76 to 16.7 m, with an average of 3.79 m (median: 3.21 m). Individual particle analyses of elemental composition showed that particles formed in combustion were mainly composed of carbon, silicon, aluminum and trace elements (e.g. Na, K, Ca, Fe). Some spherical fly ash particles contained toxic heavy metals (e.g. Pb, Cr, As, Zn), and indicated that fly ash particles acted as the main possible carriers of toxic heavy metals deposited in snow and ice of glaciers in high altitudes of central Asia. On the basis of chemical information obtained from EDX, the fly ash particles deposited in the snow could be classified into four types. Namely, Si-dominant particles, with average diameters of 3.24 m were formed by industrial coal combustion via high temperature processes in typical coal-fired heating stations and thermal power plants. Moreover, Fe-dominant particles, with average diameters of 3.82 m, and Ti-dominant spherical particles formed by lower temperature processes in foundry and iron or steel plan

关键词：天山1号冰川球形颗粒乌鲁木齐表层雪表征粉煤灰颗粒有毒重金属平均直径

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A General and Effective Method for Wall and Protrusion Separation from Facade Point Clouds

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Journal of Remote Sensing

Journal of Remote Sensing 2023年第1期3卷 296-309页

作者： Shangshu Cai Shuhang Zhang Wuming Zhang Hongchao Fan Jie Shao guangjian Yan Sisi Yu Aiguang Li and Guoqing Zhou School of Geospatial Engineering and Science Sun Yat-Sen UniversityGuangzhouChina Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) GuangdongChina Department of Civil and Environmental Engineering Norwegian University of Science and TechnologyTrondheimNorway Faculty of Geographical Science Beijing Normal UniversityBeijingChina University of Chinese Academy of Sciences BeijingChina Guilin University of Technology GuilinChina

As a critical prerequisite for semantic facade reconstruction,accurately separating wall and protrusion points from facade point clouds is *** performance of traditional separation methods is severely limited by facade conditions,including wall shapes(e.g.,nonplanar walls),wall compositions(e.g.,walls composed of multiple noncoplanar point clusters),and protrusion structures(e.g.,protrusions without regularity,repetitive,or self-symmetric features).This study proposes a more widely applicable wall and protrusion separation *** major principle underlying the proposed method is to transform the wall and protrusion separation problem as a ground filtering problem and to separate walls and protrusions using ground filtering methods,since the 2 problems can be solved using the same prior knowledge,that is,protrusions(nonground objects)protrude from walls(ground).After transformation problem,cloth simulation filter was used as an example to separate walls and protrusions in 8 facade point clouds with various *** proposed method was robust to the facade conditions,with a mean intersection over union of 90.7%,and had substantially higher accuracy compared with the traditional separation methods,including region growing-,random sample consensus-,multipass random sample consensus-based,and hybrid methods,with mean intersection over union values of 69.53%,49.52%,63.93%,and 47.07%,***,the proposed method was general,since existing ground filtering methods(including the maximum slope,progressive morphology,and progressive triangular irregular network densification filters)can also perform well.

关键词： walls separation union

System and RF Technology Challenges for 6G Integrated Sensing and Communication System

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System and RF Technology Challenges for 6G Integrated Sensin...

关于医学影像科CT与MRI报告规范化的思考

2022年全国微波毫米波会议

作者： guangjian Wang Wireless Technology Lab Huawei Technologies Co. Ltd.

6G is believed to continue transforming from connecting people, connecting things, to connect intelligence. The new applications will lead to significantly higher requirements on network performance, such as Tbit/s communication rates and millimeter-level sensing precision at the same time. It will bring the new technical challenges to system implementation, especially on the RF technologies and enabling devices. In this talk, the vision, scenarios and KPI of 6G will be presented first, then the 6G spectrum candidates and enabling technologies to realize the diverse KPI for 6G will be discussed. In addition, Challenges in implementing these targets with an emphasis on the system and RF technologies will be discussed, so as to the future research directions.

关键词：

来源： cnki会议 cnki会议评论

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中华放射学杂志 2017年第9期51卷 645-647页

作者：唐光健北京大学第一医院医学影像科 100034

医学影像科的影像检查报告,不仅是患者影像检查的结果,还是影像诊断医师提供给相关临床医师的诊断意见,是连接诊断与治疗的桥梁,是影像科生产的最终产品.特别是CT、MRI的检查报告,涉及临床医学几乎所有学科,在整个临床医学实践过程中起... 详细信息

医学影像科的影像检查报告,不仅是患者影像检查的结果,还是影像诊断医师提供给相关临床医师的诊断意见,是连接诊断与治疗的桥梁,是影像科生产的最终产品.特别是CT、MRI的检查报告,涉及临床医学几乎所有学科,在整个临床医学实践过程中起着不可或缺的作用.国际影像专业组织出台了一些影像报告规范,如前列腺影像报告和数据管理系统（prostate imaging reporting and data system,PI-RADS）、乳腺影像报告和数据管理系统（breast imaging reporting and data system,BI-RADS）以及肝脏影像报告和数据管理系统（liver imaging reporting data system,LI-RADS）等.然而,由于各种原因,我国各医疗单位（特别是基层医院）的影像检查报告方式、书写内容、规范化用语等差异巨大,存在诸多问题,如以表格方式书写报告、以诊断替代描述或仅描述不做诊断等,从而降低了影像检查报告的意义.

关键词：医学影像科报告规范 MRI CT 数据管理系统影像诊断检查报告临床医师

Advances in research on neuromyelitis optica spectrum disorders and its clinical heterogeneity

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Journal of Translational Neuroscience 2019年第4期4卷 13-22页

作者： Yi Bao Ming Jin Qi Zhao Lu Liu Yanpeng Sun Xiaoqin peng Lu Yang guangjian Liu Department of Neurology Taihe Hospital Affiliated to Hubei University of MedicineShiyanHubei 442000China

Neuromyelitis optica spectrum disorders(NMOSD)is a demyelinating disease mainly involving the optic nerve and spinal *** has recurrent and aggravating attacks and high disability *** patients have a stepwise progression,resulting in complete blindness or *** lesions contain not only the optic nerve and spinal cord,but also other neurological and non-neurological symptoms,which has clinical *** discovery of aquaporin-4-immunoglobulin G(AQP4-IgG)attributed it to autoimmune ion-channel disease,and rituximab(RTX)has achieved good clinical efficacy in the treatment of *** oligodendrocyte glycoprotein(MOG)antibodies have been found in some AQP4-IgG-negative NMOSD patients,which have different clinical and immunological features,posing new challenges to the diagnosis and treatment of NMOSD,which may require re-design and testing of new immune-targeted drugs.

关键词： neuromyelitis optica spectrum disorders(NMOSD) aquaporin-4-immunoglobulin G(AQP4-IgG) myelin oligodendrocyte glycoprotein(MOG) rituximab(RTX) paraneoplastic neurological syndrome