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Basic theory and key technologies for marine geographic information system

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Acta Oceanologica Sinica 2006年第2期25卷 80-86页

作者： SU Fenzhen YANG Xiaomei XU Jun ZHANG Tianyu LUO Jiancheng Institute of Geography Science and Resource Research Chinese Academy of Sciences Beijing100101 China Marine geographic information system Center State Key Laboratory of Geographical Information System Chinese Academy of Sciences Beijing 100101 China Department of Geography University of Wisconsin-Madison Madison Wisconsin 53706 USA

Marine geographic information system （MGIS） has great ability to deal with the spatio-temporal problems and has potential superiority when it is applied to oceanography. Using the feature extraction of oceanic phenomena as a case study, the functions of the MGIS are analyzed, and thus the position of MGIS in the oceanography is defined. Comparing the requirement of MGIS with that of the traditional GIS which has been developed in the terrestrial applications in the past four decades, the frame for the functions of MGIS is constructed. According to the established MGIS, some key technologies are discussed in detail with emphasis on the specialities which can distinguish the MGIS from the traditional GIS.

关键词： marine geographic information system remote sensing function structure data mining

A New Integrated Interpolation Method for High Missing Unstable Disease Surveillance Data—12 Urban Agglomerations,China,2009-2020

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China CDC weekly 2024年第27期6卷 670-676,I0005-I0012页

作者： Yuanhao Shi Yilan Liao The State key laboratory of Resources and Environmental information system Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina University of Chinese Academy of Science BeijingChina

Introduction:The prevalence of unstable and incomplete monitoring data significantly complicates syndromic *** data interpolation methods currently available demonstrate inadequate effectiveness in overcoming this ***:To improve the accuracy of interpolation,we propose the integration of the SHapley Additive exPlanation model(SHAP)with the structural equation model(SEM),forming a combined SHAP-SEM approach.A case study is then performed to assess the enhanced performance of this novel model compared to traditional ***:The SHAP-SEM model was utilized to develop an interpolation model employing data from the Chinese respiratory syndrome surveillance *** executed three distinct experiments to establish the model datasets,comprising a total of 100 *** performance of the model was evaluated using the root mean square error(RMSE),correlation coefficient(r),and *** findings demonstrate that the SHAP-SEM model consistently achieves superior accuracy in data interpolation,which is evident across different seasons and in overall ***:We conclude that the SHAP-SEM model demonstrates an exceptional capacity for accurately interpolating volatile and incomplete *** capability is crucial for developing a comprehensive database that is essential for conducting risk assessments related to syndromes.

关键词： interpolation incomplete exceptional

ConvNeXt-UperNet-Based Deep Learning Model for Road Extraction from High-Resolution Remote Sensing Images

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Computers, Materials & Continua 2024年第8期80卷 1907-1925页

作者： Jing Wang Chen Zhang Tianwen Lin geographic information and Tourism College Chuzhou UniversityChuzhou239000China Anhui Province key laboratory of Physical geographic Environment Chuzhou UniversityChuzhou239000China

When existing deep learning models are used for road extraction tasks from high-resolution images,they are easily affected by noise factors such as tree and building occlusion and complex backgrounds,resulting in incomplete road extraction and low *** propose the introduction of spatial and channel attention modules to the convolutional neural network ***,ConvNeXt is used as the backbone network,which cooperates with the perceptual analysis network UPerNet,retains the detection head of the semantic segmentation,and builds a new model ConvNeXt-UPerNet to suppress noise *** on the open-source DeepGlobe and CHN6-CUG datasets and introducing the DiceLoss on the basis of CrossEntropyLoss solves the problem of positive and negative sample *** results show that the new network model can achieve the following performance on the DeepGlobe dataset:79.40%for precision(Pre),97.93% for accuracy(Acc),69.28% for intersection over union(IoU),and 83.56% for mean intersection over union(MIoU).On the CHN6-CUG dataset,the model achieves the respective values of 78.17%for Pre,97.63%for Acc,65.4% for IoU,and 81.46% for *** with other network models,the fused ConvNeXt-UPerNet model can extract road information better when faced with the influence of noise contained in high-resolution remote sensing *** also achieves multiscale image feature information with unified perception,ultimately improving the generalization ability of deep learning technology in extracting complex roads from high-resolution remote sensing images.

关键词： Deep learning semantic segmentation remote sensing imagery road extraction

FIBTNet:Building Change Detection for Remote Sensing Images Using Feature Interactive Bi-Temporal Network

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Computers, Materials & Continua 2024年第9期80卷 4621-4641页

作者： Jing Wang Tianwen Lin Chen Zhang Jun Peng School of geographic information and Tourism Chuzhou UniversityChuzhou239000China Anhui Province key laboratory of Physical geographic Environment Chuzhou UniversityChuzhou239000China

In this paper,a feature interactive bi-temporal change detection network(FIBTNet)is designed to solve the problem of pseudo change in remote sensing image building change *** network improves the accuracy of change detection through bi-temporal feature *** designs a bi-temporal feature exchange architecture(EXA)and a bi-temporal difference extraction architecture(DFA).EXA improves the feature exchange ability of the model encoding process through multiple space,channel or hybrid feature exchange methods,while DFA uses the change residual(CR)module to improve the ability of the model decoding process to extract different features at multiple ***,at the junction of encoder and decoder,channel exchange is combined with the CR module to achieve an adaptive channel exchange,which further improves the decision-making performance of model feature *** results on the LEVIR-CD and S2Looking datasets demonstrate that iCDNet achieves superior F1 scores,Intersection over Union(IoU),and Recall compared to mainstream building change detectionmodels,confirming its effectiveness and superiority in the field of remote sensing image change detection.

关键词： Change detection change residual module feature exchange mechanism feature fusion

Integrating remote sensing and 3-PG model to simulate the biomass and carbon stock of Larix olgensis plantation

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Forest Ecosystems 2024年第4期11卷 543-555页

作者： Yu Bai Yong Pang Dan Kong key laboratory of National Forestry and Grassland Administration on Forestry Remote Sensing and information system Institute of Forest Resource Information

Accurate estimations of biomass and its temporal dynamics are crucial for monitoring the carbon cycle in forest ecosystems and assessing forest carbon sequestration *** studies have shown that integrating process-based models(PBMs)with remote sensing data can enhance simulations from stand to regional scales,significantly improving the ability to simulate forest growth and carbon stock ***,the utilization of PBMs for large-scale simulation of larch carbon storage distribution is still *** this study,we applied the parameterized 3-PG(Physiological Principles Predicting Growth)model across the Mengjiagang Forest Farm(MFF)to make broad-scale predictions of the biomass and carbon stocks of Larix olgensis *** model was used to simulate average diameter at breast height(DBH)and total biomass,which were later validated with a wide range of observation data including sample plot data,forest management inventory data,and airborne laser scanning *** results showed that the 3-PG model had relatively high accuracy for predicting both DBH and total biomass at stand and regional scale,with determination coefficients ranging from 0.78 to *** on the estimation of total biomass,we successfully produced a carbon stock map of the Larix olgensis plantation in MFF with a spatial resolution of 20 m,which helps with relevant management *** findings indicate that the integration of 3-PG model and remote sensing data can well predict the biomass and carbon stock at regional and even larger *** addition,this integration facilitates the evaluation of forest carbon sequestration capacity and the development of forest management plans.

关键词： 3-PG model Larch Biomass Carbon stock ALS

A Practical Regular LDPC Coded Scheme for Physical-Layer information Security

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China Communications 2024年第5期21卷 190-201页

作者： Du Junyi CETC key laboratory of Avionic information system Southwest China Institute of Electronic TechnologyChengdu 610036China

In this paper,we aim to design a practical low complexity low-density parity-check(LDPC)coded scheme to build a secure open channel and protect information from *** this end,we first propose a punctured LDPC coded scheme,where the information bits in a codeword are punctured and only the parity check bits are transmitted to the *** further propose a notion of check node type distribution and derive multi-edge type extrinsic information transfer functions to estimate the security performance,instead of the well-known weak metric bit error *** optimize the check node type distribution in terms of the signal-to-noise ratio(SNR)gap and modify the progressive edge growth algorithm to design finite-length *** results show that our proposed scheme can achieve a lower computational complexity and a smaller security gap,compared to the existing scrambling and puncturing schemes.

关键词： extrinsic information transfer function physical layer scheme secure open channel security gap

An angular blinking jamming method based on electronically controlled corner reflectors

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Journal of systems Engineering and Electronics 2024年第2期35卷 330-338页

作者： GAN Lin WU Zehao WANG Xuesong LI Jianbing State key laboratory of Complex Electromagnetic Environmental Effects on Electronics and information system National University of Defense TechnologyChangsha 410073China

Passive jamming is believed to have very good potential in countermeasure *** this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is *** amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying *** of the decoying effect on corner reflectors’radar cross section and positions are analyzed and *** show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.

关键词： monopulse radar angular blinking jamming corner reflector amplitude-comparison angle measurement metasurface

Control of Virtual Synchronous Generator for Frequency Regulation Using a Coordinated Self-adaptive Method

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CSEE Journal of Power and Energy systems 2024年第1期10卷 175-184页

作者： Hongwei Fang Zhiwei Yu School of Electrical and information Engineering and key laboratory of Tianjin Electric Power system Simulation and Control Tianjin UniversityTianjin 300072China

Power inverter adopting virtual synchronous generator(VSG)control can provide inertia support for distributed generation ***,it cannot take into account the dynamic regulation characteristics of ***,when the system encounters a sudden change in load or disturbance,the dynamic process of frequency regulation will be greatly *** view of this issue,an improved VSG control strategy based on a coordinated self-adaptive(CSA)method is *** time domain analysis method is used to study the influences of virtual inertia and damping parameter perturbation on the system steady and dynamic ***,in order to make the control strategy suitable for large load changes and suppress frequency variations beyond the limit,the secondary frequency modulation is introduced into the control *** the coordinated adaptive control of virtual inertia,virtual damping and frequency modulation,the dynamic performance of vSG frequency regulation can be obviously *** and experiment results have verified the effectiveness of the proposed CSA control strategy.

关键词： Coordinated self-adaptive method frequency regulation time domain analysis virtual synchronous generator

Spatio-temporal patterns of temperature extremes and their response to atmospheric circulation factors in China from 1961 to 2020

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Journal of geographical Sciences 2024年第10期34卷 1883-1903页

作者： LUO Yuanbo ZHOU Yuke ZHOU Chenghu State key laboratory of Resources and Environmental information system Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China key laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCAsBeijing 100101China

Changes in surface temperature extremes have become a global *** on the daily lowest temperature(TN)and daily highest temperature(TX)data from 2138weather stations in China from 1961 to 2020,we calculated 14 extreme temperature indices to analyze the characteristics of extreme temperature *** widespread changes observed in all extreme temperature indices suggest that China experienced significant warming during this ***,the cold extreme indices,such as cold nights,cold days,frost days,icing days,and the cold spell duration index,decreased significantly by-6.64,-2.67,-2.96,-0.97,and-1.01 days/decade,*** contrast,we observed significant increases in warm extreme *** number of warm nights,warm days,summer days,tropical nights,and warm spell duration index increased by 8.44,5.18,2.81,2.50,and 1.66d/decade,*** addition,the lowest TN,highest TN,lowest TX,and highest TX over the entire period rose by 0.47,0.22,0.26,and 0.16℃/decade,***,using Pearson's correlation and wavelet coherence analyses,this study identified a strong association between extreme temperature indices and atmospheric circulation factors,with varying correlation strengths and resonance periods across different time-frequency domains.

关键词： temperature changes global warming atmospheric circulation wavelet coherence analysis China