检索结果-南通市图书馆

Random Forest-Based Snow Cover Mapping in China Using Fengyun-3B VIRR Data

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2023年第5期37卷 666-689页

作者： yuchen xie Yonghong LIU Yeping ZHANG Fuzhong WENG Shanyou ZHU Zhaojun ZHENG Shihao TANG School of Remote Sensing&Geomatics Engineering Nanjing University of Information Science&TechnologyNanjing 210044 CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing 100081 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 National Satellite Meteorological Centre China Meteorological AdministrationBeijing 100081

Currently,there is variability in the spectral band thresholds for snow cover recognition using remote sensing in different regions and for complex *** Fengyun-3B Visible and Infra-Red Radiometer(FY-3B VIRR)satellite data,we applied random forest(RF)methodology and selected 13 feature variables to obtain snow cover.A training set was generated,containing approximately 1 million snow and nonsnow samples obtained in China from the snow monitoring reports issued by the National Satellite Meteorological Centre and four snow cover products from the Interactive Multi-sensor Snow and Ice Mapping System(IMS),the FY-3B Multi-Sensor Synergy(MULSS),the Moderate Resolution Imaging Spectroradiometer(MODIS)snow cover product(MYD10A1),and the National Cryosphere Desert Data Center(NCDC).This training set contained many different samples of cloud types and snow under forest cover to help effectively distinguish snow and clouds and improve the recognition rate of snow under forest ***,two RF snow cover recognition models were constructed for the snow and nonsnow seasons and they were used to conduct daily snow cover recognition in China from 2011 to *** results show that the RF models constructed based on FY-3B VIRR data have good recognition performance for shallow snow,understory snow,and snow on the Qinghai–Tibetan *** recognition accuracy against weather stations and the spatial consistency with the IMS product are better than the MULSS,MYD10A1,and NCDC *** overall accuracy of the RF product is 90.6%,and the recall rate is 93.8%.The omission and commission errors are 6.2%and11.1%,*** other existing snow cover algorithms,the established RF model skips the complicated atmospheric correction and cloud identification processes and does not involve external auxiliary data;thus,it is more easily popularized and operationally applicable to generating long-time series snow cover products.

关键词： snow identification random forest Fengyun-3B Visible and Infra-Red Radiometer feature selection

Phytophthora Effectors Modulate Genome-wide Alternative Splicing of Host mRNAs to Reprogram Plant Immunity

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2020年第10期13卷 1470-1484页

作者： Jie Huang Xinyu Lu Hongwei Wu yuchen xie Qian Peng Lianfeng Gu Juyou Wu Yuanchao Wang Anireddy SNReddy Suomeng Dong Department of Plant Pathology Nanjing Agricultural UniversityNanjing 210095China Basic Forestry and Proteomics Research Center College of ForestryFujian Agriculture and Forestry UniversityFuzhou 350002China State Key Laboratory of Crop Genetics and Germplasm Enhancement College of HorticultureNanjing Agricultural UniversityNanjing 210095China Colorado State University Program in Cell and Molecular BiologyFort CollinsCO 80523USA Key Laboratory of Integrated Management of Crop Diseases and Pests(Ministry of Education) Nanjing 210095China The Key Laboratory of Plant Immunity Nanjing Agricultural UniversityNanjing 210095China

Alternative splicing(AS)of pre-mRNAs increases transcriptome and proteome diversity,regulates gene expression through multiple mechanisms,and plays important roles in plant development and stress ***,the prevalence of genome-wide plant AS changes during infection and the mechanisms by which pathogens modulate AS remain poorly ***,we examined the global AS changes in tomato leaves infected with Phytophthora infestans,the infamous Irish famine *** show that more than 2000 genes exhibiting significant changes in AS are not differentially expressed,indicating that AS is a distinct layer of transcriptome reprogramming during plant-pathogen ***,our results show that *** subverts host immunity by repressing the AS of positive regulators of plant immunity and promoting the AS of susceptibility *** study the underlying mechanism,we established a luminescence-based AS reporter system in Nicotiana benthamiana to screen pathogen effectors modulating plant *** identified nine splicing regulatory effectors(SREs)from 87 *** *** studies revealed that SRE3 physically binds U1-70K to manipulate the plant AS machinery and subsequently modulates AS-mediated plant *** study not only unveils genome-wide plant AS reprogramming during infection but also establishes a novel AS screening tool to identify SREs from a wide range of plant pathogens,providing opportunities to understand the splicing regulatory mechanisms through which pathogens subvert plant immunity.

关键词： late blight Phytophthora infestans alternative splicing splicing regulatory effectors plant immunity tomato

Different fundus imaging modalities and technical factors in AI screening for diabetic retinopathy:a review

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Eye and Vision 2020年第1期7卷 201-213页

作者： Gilbert Lim Valentina Bellemo yuchen xie Xin Q.Lee Michelle Y.T.Yip Daniel S.W.Ting School of Computing National University of SingaporeSingaporeSingapore Singapore Eye Research Institute Singapore National Eye CentreSingaporeSingapore Duke-NUS Medical School National University of Singapore11 Third Hospital Road AvenueSingapore 168751Singapore Vitreo-Retinal Service Singapore National Eye Center11 Third Hospital Road AvenueSingapore 168751Singapore Artificial Intelligence in Ophthalmology Singapore Eye Research Institute11 Third Hospital Road AvenueSingapore 168751Singapore

Background:Effective screening is a desirable method for the early detection and successful treatment for diabetic retinopathy,and fundus photography is currently the dominant medium for retinal imaging due to its convenience and *** screening using fundus photographs has however involved considerable costs for patients,clinicians and national health systems,which has limited its application particularly in less-developed *** advent of artificial intelligence,and in particular deep learning techniques,has however raised the possibility of widespread automated *** text:In this review,we first briefly survey major published advances in retinal analysis using artificial *** take care to separately describe standard multiple-field fundus photography,and the newer modalities of ultrawide field photography and smartphone-based ***,we consider several machine learning concepts that have been particularly relevant to the domain and illustrate their usage with extant ***:In the ophthalmology field,it was demonstrated that deep learning tools for diabetic retinopathy show clinically acceptable diagnostic performance when using colour retinal fundus *** intelligence models are among the most promising solutions to tackle the burden of diabetic retinopathy management in a comprehensive ***,future research is crucial to assess the potential clinical deployment,evaluate the cost-effectiveness of different DL systems in clinical practice and improve clinical acceptance.

关键词： Artificial intelligence Deep learning Diabetic retinopathy Fundus photographs Retinal imaging modalities Survey

Local-contrastive-learning machine with both generalization and adversarial robustness: A statistical physics analysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 109-123页

作者： Mingshan xie yuchen Wang Haiping Huang PMI Lab School of Physics Sun Yat-sen University Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices Sun Yat-sen University

Distinct from human cognitive processing, deep neural networks trained by backpropagation can be easily fooled by adversarial examples. To design a semantically meaningful representation learning, we discard backpropagation, and instead, propose a local contrastive learning, where the representations for the inputs bearing the same label shrink(akin to boson) in hidden layers,while those of different labels repel(akin to fermion). This layer-wise learning is local in nature, being biologically plausible.A statistical mechanics analysis shows that the target fermion-pair-distance is a key parameter. Moreover, the application of this local contrastive learning to MNIST benchmark dataset demonstrates that the adversarial vulnerability of standard perceptron can be greatly mitigated by tuning the target distance, i.e., controlling the geometric separation of prototype manifolds.

关键词： machine learning statistical mechanics adversarial robustness neural networks

卫星导航信号无模糊抗多径码相关参考波形设计技术

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

国防科技大学学报 2019年第4期41卷 136-143页

作者：徐成涛刘哲谢郁辰国防科技大学系统工程学院湖南长沙410073 国防科技大学电子科学学院湖南长沙410073

针对目前卫星导航接收机码环多径抑制技术在二进制偏移副载波类信号下鉴别曲线可能出现多个稳定跟踪位置,导致接收机存在伪距测量的系统性误差的问题,提出最优鉴别曲线设计技术,采用奇异值优化的最小二乘方法,设计无多余跟踪点的本地码... 详细信息

针对目前卫星导航接收机码环多径抑制技术在二进制偏移副载波类信号下鉴别曲线可能出现多个稳定跟踪位置,导致接收机存在伪距测量的系统性误差的问题,提出最优鉴别曲线设计技术,采用奇异值优化的最小二乘方法,设计无多余跟踪点的本地码相关参考波形。从多径误差包络和跟踪精度两方面,对基于最优鉴别曲线的二进制偏移副载波信号码相关参考波形的设计性能进行验证评估。仿真结果表明:该方法可实现二进制偏移副载波信号在有限接收带宽下的无模糊鉴别曲线设计。以前端带宽为8.184MHz时的BOC(1,1)信号为例,设计的码相关参考波形相比W2波形,多径误差包络面积增加了61.8%,而跟踪精度提高了4~5dB。

关键词：二进偏移制副载波信号最优鉴别曲线码相关参考波形多径抑制无模糊跟踪

A Software Defined Receiver for GNSS/INS Ultra-Tight Coupling Simulation

在线全文

学校读者我要写书评

暂无评论

A Software Defined Receiver for GNSS/INS Ultra-Tight Couplin...

第十一届中国卫星导航年会

作者： yuchen xie Pengcheng Ma Zukun Lu Feiqiang Chen Feixue Wang National University of Defense Technology

The performance of navigation can be significantly enhanced by coupling the Global Navigation Satellite System(GNSS) and the Inertial Navigation System(INS) because the characteristics of these two sy

关键词： GNSS/INS Ultra-Tight Coupling Software Defined Receiver Extended Kalman Filter

来源： cnki会议 cnki会议 cnki会议评论

在线全文

学校读者我要写书评

暂无评论

GNSS/INS超紧组合导航综述

国防科技大学学报 2023年第5期45卷 48-59页

作者：倪少杰李诗扬谢郁辰邓丁国防科技大学电子科学学院湖南长沙410073

卫星/惯性超紧组合导航系统以其定位精度高、动态性能优良、抗干扰能力强等特性成为组合导航领域的研究热点。介绍了卫星/惯性超紧组合的定位原理,基于对技术原理的分析,比较超紧组合模式相对于其他组合模式的优势特点;以高动态下超紧... 详细信息

卫星/惯性超紧组合导航系统以其定位精度高、动态性能优良、抗干扰能力强等特性成为组合导航领域的研究热点。介绍了卫星/惯性超紧组合的定位原理,基于对技术原理的分析,比较超紧组合模式相对于其他组合模式的优势特点;以高动态下超紧组合技术及卫星/微惯性单元超紧组合为代表介绍国内外研究现状;总结了亟待研究的容错控制技术、神经网络辅助、多传感器辅助超紧组合等关键技术,并对卫星/惯性超紧组合向着低成本、高精度、强稳定趋势发展的前景进行展望。

关键词：超紧组合深组合全球导航卫星系统惯性导航系统

Research on Spoofing Detection based on C/N0 measurements for GNSS array receivers

在线全文

学校读者我要写书评

暂无评论

Research on Spoofing Detection based on C/N0 measurements fo...

T-Distributed Stochastic Neighbor Embedding with Gauss Initialization of Quantum Whale Optimization Algorithm

第十四届中国卫星导航年会

作者： Jinyuan Liu yuchen xie Feiqiang Chen Shaojie Ni Guangfu Sun College of Electronic Science and Engineering National University of Defense Technology

In recent years,Global Navigation Satellite System(GNSS) spoofing detection techniques have attracted wide *** with jamming,spoofing which always hides in the shadows has stronger concealment leading to more threat to the security of ***-to-noise ratio(C/N) is one of the important measurements of *** may cause abnormal changes in the C/N,but the variations of the C/N are not obvious in most cases,and it is liable to cause false alarm in the presence of *** on antenna arrays,this paper theoretically derives the effective C/N model of array receivers as spoofing successfully or unsuccessfully captures tracking *** we demonstrate that the C/N single difference(CSD) between satellites can be the testing statistic for spoofing *** results show that the proposed method can detect the abnormal C/N features of counterfeit signals after anti-jamming for the antenna *** method does not require modifications to the hardware configuration of conventional receivers and can provide an effective defense for array receiver in the combination of jamming and spoofing attacks.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

T-Distributed Stochastic Neighbor Embedding with Gauss Initi...