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Status and trends in the stability of the three largest ice shelves in Antarctica

Science China Earth Sciences 2024年第8期67卷 2615-2632页

作者： Rongxing LI Guojun LI Lu AN Menglian XIA Da LV Yuan CHENG Aiguo ZHAO Tian CHANG Xiangbin CUI Shengkai ZHANG Shijie LIU Yixiang TIAN Weian WANG center for Spatial information Science and Sustainable Development Applications Tongji UniversityShanghai 200092China College of Surveying and Geo-informatics Tongji UniversityShanghai 200092China postdoctoral research station of Shanghai Surveying and Mapping Institute Shanghai 200063China Key Laboratory of Spatial-temporal Big Data Analysis and Application of Natural Resources in Megacities Shanghai 200063China Institute for Conservation of Cultural Heritage School of Cultural Heritage and Information ManagementShanghai UniversityShanghai 200444China Polar research Institute of China Shanghai 200136China Chinese Antarctic center of Surveying and Mapping Wuhan UniversityWuhan 430079China

The Ross,Filchner-Ronne,and Amery ice shelves are the three largest ice shelves in Antarctica,playing a crucial role in supporting the Antarctic ice ***,current studies on the stability of the three largest ice shelves primarily focus on singular or limited factors,lacking a comprehensive assessment of multiple *** systematically and in-depth study the stability and trend of the three largest ice shelves,we comprehensively collected and analyzed key parameters,including elevation changes,basal melting,surface meltwater,major rifts propagation rate,suture zones,ice front area change rate,grounding lines,ice velocity,and mass ***,we selected the collapsed Larsen B Ice Shelf(LBIS),the rapidly changing and structurally weakened Pine Island Ice Shelf(PIIS),and the accelerating Totten Ice Shelf(TIS)as reference ice *** comparing and analyzing the key parameters between these reference ice shelves and the three largest ice shelves,we find the status and trends in the stability of the *** findings reveal that most key parameters of the three largest ice shelves present relatively minor variations compared to those of the reference ice ***,50%of the parameters are smaller than those of the accelerating TIS,88%are smaller than those of the rapidly changing PIIS,and all parameters are smaller than those of the collapsed ***,after analyzing parameters that are not smaller than those of the TIS,it is observed that they remain in a stable ***,the three largest ice shelves are currently undergoing natural changes that do not threaten their stability in the short ***,the evolution of the ice shelves under global climate change remains uncertain,making long-term observation and monitoring essential to assess their impact on sea level rise.

关键词： Three largest ice shelves in Antarctica Key parameters Remote sensing monitoring Ice shelf stability Sea level change

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Mitigating Straggler Effect in Federated Learning Based on Reconfigurable Intelligent Surface over Internet of Vehicles

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China Communications 2024年第8期21卷 62-78页

作者： Li Zejun Wu Hao Lu Yunlong Dai Yueyue Ai Bo School of Electronic and information Engineering Beijing Jiaotong UniversityBeijing 100044China Frontiers Science center for Smart High-Speed Railway System Beijing 100044China Beijing Engineering research center of High-Speed Railway Broadband Mobile Communications Beijing 100044China research center of 6G Mobile Communications School of Cyber Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

To protect vehicular privacy and speed up the execution of tasks,federated learning is introduced in the Internet of Vehicles(IoV)where users execute model training locally and upload local models to the base station without massive raw data ***,heterogeneous computing and communication resources of vehicles cause straggler effect which weakens the reliability of federated *** out vehicles with limited resources confines the training *** a result,the accuracy and applicability of federated learning models will be *** mitigate the straggler effect and improve performance of federated learning,we propose a reconfigurable intelligent surface(RIS)-assisted federated learning framework to enhance the communication reliability for parameter transmission in the ***,we optimize the phase shift of RIS to achieve a more reliable communication *** addition,we define vehicular competence to measure both vehicular trustworthiness and *** on the vehicular competence,the straggler effect is mitigated where training tasks of computing stragglers are offloaded to surrounding vehicles with high *** experiment results verify that our proposed framework can improve the reliability of federated learning in terms of computing and communication in the IoV.

关键词： reliable federated learning RIS straggler effect vehicular competence

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Mixed D-vine copula-based conditional quantile model for stochastic monthly streamflow simulation

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Water Science and Engineering 2024年第1期17卷 13-20页

作者： Wen-zhuo Wang Zeng-chuan Dong Tian-yan Zhang Li Ren Lian-qing Xue Teng Wu College of Water Resources and Hydrology Hohai UniversityNanjing 210098China Yellow River research center Hohai UniversityNanjing 210098China

Copula functions have been widely used in stochastic simulation and prediction of ***,existing models are usually limited to single two-dimensional or three-dimensional copulas with the same bivariate block for all *** address this limitation,this study developed a mixed D-vine copula-based conditional quantile model that can capture temporal *** model can generate streamflow by selecting different historical streamflow variables as the conditions for different months and by exploiting the conditional quantile functions of streamflows in different months with mixed D-vine *** up-to-down sequential method,which couples the maximum weight approach with the Akaike information criteria and the maximum likelihood approach,was used to determine the structures of multivariate Dvine *** developed model was used in a case study to synthesize the monthly streamflow at the Tangnaihai hydrological station,the inflow control station of the Longyangxia Reservoir in the Yellow River *** results showed that the developed model outperformed the commonly used bivariate copula model in terms of the performance in simulating the seasonality and interannual variability of *** model provides useful information for water-related natural hazard risk assessment and integrated water resources management and utilization.

关键词： Stochastic monthly streamflow simulation Mixed D-vine copula Conditional quantile model Up-to-down sequential method Tangnaihai hydrological station

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Joint Effects of Multipollutant Mixtures on Mortality in Chengdu,China

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Biomedical and Environmental Sciences 2024年第1期37卷 112-116页

作者： ZHANG Ying TIAN Qi Qi HU Wen Dong ZHANG Shao Bo WANG Shi Gong ZHENG Can Jun Plateau Atmosphere and Environment Key Laboratory of Sichuan Province School of Atmospheric SciencesChengdu University of Information TechnologyChengdu 610225SichuanChina Yunnan R&D Institute of Natural Disaster on Chengdu University of information Technology Kunming 650034YunnanChina Chengdu Plain Urban Meteorology and Environment Sichuan Provincial Field Scientific Observation and research station Chengdu 610225SichuanChina Chinese center for Disease Control and Prevention National Institute for Communicable Disease Control and PreventionBeijing 102206China

Significant epidemiological research has revealed that exposure to air pollution is substantially associated with numerous detrimental health consequences^([1-3]).The negative health effects of individual air pollutants(e.g.,fine particulate matter:PM_(2.5);nitrogen dioxide:NO_(2);carbon monoxide,CO;or ozone:O_(3))have been widely explored^([4]).However,humans are constantly exposed to multipollutant mixtures in real life,and biological responses to inhaled pollutants are likely to depend on the interplay of pollutant ***,it is critical and imperative to explore the joint effects of multipollutant mixtures on human beings.

关键词： mixtures monoxide consequences

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Towards accurate mapping of loess waterworn gully by integrating google earth imagery and DEM using deep learning

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International Soil and Water Conservation research 2024年第1期12卷 13-28页

作者： Rong Chen Yi Zhou Zetao Wang Ying Li Fan Li Feng Yang School of Geography and tourism Shaanxi Normal UniversityXi'an710119China National Experiment and Teaching Demonstration center for Geography Xi'an710119China SuperMap Software Co. Ltd.Beijing100015China School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen518055China

Accurate mapping of loess waterworn gully(LWG)is essential to further study gully erosion and geomorphological evolution for the Chinese Loess Plateau(CLP).Due to the vertical joint and collapsibility of loess,LWGs have the characteristics of zigzag and unique slope abruptness under synthetic action of hydraulic force and *** forces existing LWG mapping methods to either focus on the improvement of mapping accuracy or center on the increase of mapping ***,simultaneously achieving accurate and efficient mapping of LWG is still in its infancy under complex topographic ***,we proposed a method that innovatively integrates the loess slope abruptness feature into an improved deep learning semantic segmentation framework for LWG mapping using 0.6 m Google imagery and 5 m DEM *** selected four study areas representing typical loess landforms to test the performance of our *** proposed method can achieve satisfactory mapping results,with the F1 score,mean Intersection-over-Union(mIoU),and overall accuracy of 90.5%,85.3%,and 92.3%,*** addition,the proposed model also showed significant accuracy improvement by inputting additional topographic information(especially the slope of slope).Compared with existing algorithms(Random forests,original DeepLabV3+,and Unet),the proposed approach in this study achieved a better accuracy-efficiency ***,the method can ensure high accuracy and efficiency of the LWG mapping for different loess landform types and can be extended to study various loess gully mapping and water and soil conservation.

关键词： Loess waterworn gully Topographic information Mapping Deep learning Soil erosion Loess plateau

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Ecology and risks of the global plastisphere as a newly expanding microbial habitat

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The Innovation 2024年第1期5卷 49-58页

作者： Changchao Li Michael RGillings Chao Zhang Qinglin Chen Dong Zhu Jie Wang Kankan Zhao Qicheng Xu Polly Hangmei Leung Xiangdong Li Jian Liu Ling Jin Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina Environment research Institute Shandong UniversityQingdao 266237China State Key Laboratory of Marine Pollution City University of Hong KongKowloon TongHong KongChina ARC Centre of Excellence in Synthetic Biology Faculty of Science and EngineeringMacquarie UniversitySydneyNSW 2109Australia Key Laboratory of Urban Environment and Health Ningbo Urban Environment Observation and Research StationInstitute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China Institute of Soil and Water Resources and Environmental Science College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China Jiangsu Collaborative Innovation center for Solid Organic Waste Resource Utilization Nanjing Agricultural UniversityNanjing 210095China Department of Health Technology and Informatics and research Institute for Future Food The Hong Kong Polytechnic UniversityKowloonHong KongChina Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China

Plastic offers a new niche for microorganisms,the *** everincreasing emission of plastic waste makes it critical to understand the microbial ecology of the plastisphere and associated ***,we present a global fingerprint of the plastisphere,analyzing samples collected from freshwater,seawater,and terrestrial *** plastisphere assembles a distinct microbial community that has a clearly higher heterogeneity and a more deterministically dominated assembly compared to natural *** coexistence patterns—loose and fragile networks with mostly specialist linkages among microorganisms that are rarely found in natural habitats—are seen in the *** microbiomes generally have a great potential to metabolize organic compounds,which could accelerate carbon *** involved in the nitrogen cycle are also altered in the plastisphere,especially in freshwater plastispheres,where a high abundance of denitrifiers may increase the release of nitrite(aquatic toxicant)and nitrous oxide(greenhouse gas).Enrichment of animal,plant,and human pathogens means that the plastisphere could become an increasingly mobile reservoir of harmful *** findings highlight that if the trajectory of plastic emissions is not reversed,the expanding plastisphere could pose critical planetary health challenges.

关键词： reservoir mostly habitat

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Residual Feature Attentional Fusion Network for Lightweight Chest CT Image Super-Resolution

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Computers, Materials & Continua 2023年第6期75卷 5159-5176页

作者： Kun Yang Lei Zhao Xianghui Wang Mingyang Zhang Linyan Xue Shuang Liu Kun Liu College of Quality and Technical Supervision Hebei UniversityBaoding071002China Hebei Technology Innovation center for Lightweight of New Energy Vehicle Power System Baoding071002China postdoctoral research station of Optical Engineering Hebei UniversityBaoding071000China

The diagnosis of COVID-19 requires chest computed tomography(CT).High-resolution CT images can provide more diagnostic information to help doctors better diagnose the disease,so it is of clinical importance to study super-resolution(SR)algorithms applied to CT images to improve the reso-lution of CT ***,most of the existing SR algorithms are studied based on natural images,which are not suitable for medical images;and most of these algorithms improve the reconstruction quality by increasing the network depth,which is not suitable for machines with limited *** alleviate these issues,we propose a residual feature attentional fusion network for lightweight chest CT image super-resolution(RFAFN).Specifically,we design a contextual feature extraction block(CFEB)that can extract CT image features more efficiently and accurately than ordinary residual *** addition,we propose a feature-weighted cascading strategy(FWCS)based on attentional feature fusion blocks(AFFB)to utilize the high-frequency detail information extracted by CFEB as much as possible via selectively fusing adjacent level feature ***,we suggest a global hierarchical feature fusion strategy(GHFFS),which can utilize the hierarchical features more effectively than dense concatenation by progressively aggregating the feature information at various *** experiments show that our method performs better than most of the state-of-the-art(SOTA)methods on the COVID-19 chest CT *** detail,the peak signal-to-noise ratio(PSNR)is 0.11 dB and 0.47 dB higher on CTtest1 and CTtest2 at×3 SR compared to the suboptimal method,but the number of parameters and multi-adds are reduced by 22K and 0.43G,*** method can better recover chest CT image quality with fewer computational resources and effectively assist in COVID-19.

关键词： Super-resolution COVID-19 chest CT lightweight network contextual feature extraction attentional feature fusion

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Trunk volume estimation of irregular shaped Populus euphratica riparian forest using TLS point cloud data and multivariate prediction models

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Forest Ecosystems 2023年第1期10卷 1-11页

作者： Asadilla Yusup Umut Halik Maierdang Keyimu Tayierjiang Aishan Abdulla Abliz Babierjiang Dilixiati Jianxin Wei College of Ecology and Environment Ministry of Education Key Laboratory of Oasis EcologyXinjiang UniversityUrumqi830046China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of ScienceUrumqi830011China Cele National station of Observation and research for Desert-Grassland Ecosystems Cele848300China College of tourism Key Laboratory of Sustainable Development of Xinjiang's Historical and Cultural TourismXinjiang UniversityUrumqi830046China Xinjiang Laser Radar Engineering Technology center Urumqi830002China

Background: Trunk volume(Vt) is an essential parameter for estimating forest stand volume, biomass, and carbon sequestration potential. As the dominant tree species in desert riparian forests, Euphrates poplar(Populus euphratica) has a high proportion of irregularly shaped tree trunks along the Tarim River, NW China, where the habitat is very fragile owing to long-term water stress. This causes uncertainty in estimation accuracy as well as technical challenges for forest surveys. Our study aimed to acquire P. euphratica Vtusing terrestrial laser scanning(TLS) and to establish a species-specific Vtprediction ***: A total of 240 individual trees were measured by TLS multiple-station in 12 sampling plots in three sections along the lower reaches of the Tarim River. Vtwas calculated by a definite integration method using trunk diameters(Di) at every 0.1-m tree height obtained from TLS, and all data were split randomly into two sets:70% of data were used to estimate the model parameter calibration, and the remaining 30% were used for model validation. Sixteen widely used candidate tree Vtestimation models were fitted to the TLS-measured Vtand tree structural parameter data, including tree height(H), diameter at breast height(DBH), and basal diameter(BD). All model performances were evaluated and compared by the statistical parameters of determination coefficient(R^(2)),root mean square error(RMSE), Bayesian information criterion(BIC), mean prediction error(ME), mean absolute error(MAE), and modeling efficiency(EF), and accordingly the best model was ***: TLS point cloud reflection intensity(RI) has advantageous in the extraction of data from irregular tree trunk structures. The P. euphratica tree Vtvalues showed obvious differences at the same tree height(H). There was no significant correlation between Vtand H(R^(2)=0.11, P < 0.01), which reflected the irregularity of P. euphratica trunk shape in the study area. Among all the models, model(14): Vt

关键词： Populus euphratica Trunk volume Terrestrial laser scanning(TLS) Reflection intensity Tarim river

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Age of Transmission-Optimal Scheduling for State Update of Multi-Antenna Cellular Internet of Things

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China Communications 2022年第4期19卷 302-314页

作者： Song Li Min Li Ruirui Chen Yanjing Sun School of information and Control Engineering China University of Mining and TechnologyXuzhou 221116China Artificial Intelligence research Institute China University of Mining and TechnologyXuzhou 221116China Xuzhou Engineering research center of Intelligent Industry Safety and Emergency Collaboration Xuzhou 221116China

Timely information updates are critical for real-time monitoring and control applications in the Internet of Things(IoT). In this paper, we consider a multi-antenna cellular IoT for state update where a base station(BS) collects information from randomly distributed IoT nodes through time-varying ***, multiple IoT nodes are allowed to transmit their state update simultaneously in a spatial multiplex manner. Inspired by age of information(AoI),we introduce a novel concept of age of transmission(AoT) for the sceneries in which BS cannot obtain the generation time of the packets waiting to be transmitted. The deadline-constrained AoT-optimal scheduling problem is formulated as a restless multi-armed bandit(RMAB) problem. Firstly, we prove the indexability of the scheduling problem and derive the closed-form of the Whittle index. Then, the interference graph and complementary graph are constructed to illustrate the interference between two nodes. The complete subgraphs are detected in the complementary graph to avoid inter-node interference. Next, an AoT-optimal scheduling strategy based on the Whittle index and complete subgraph detection is ***, numerous simulations are conducted to verify the performance of the proposed strategy.

关键词： age of transmission information freshness cellular IoT restless multi-armed bandit Whittle index

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北京城区交通时间可达性测度及其空间特征分析（英文）

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Journal of Geographical Sciences 2016年第12期26卷 1754-1768页

作者：王江浩邓羽宋辞田大江 Institute of Geographic Sciences and Natural Resources research CAS Jiangsu center for Collaborative Innovation in Geographical information Resource Development and Application the postdoctoral research station of tourism information research center Beijing Union University & University of International Business and Economics School of information Technology and Management University of International Business and Economics

Construction of road infrastructure is fundamental to city operation and development, as well as an important pathway and focus in physical urban-rural integration. The long-term implementation of a system of ring roads plus radiating roads in Beijing has strongly impacted urban infrastructure construction and space-time accessibility. Particularly, recent rapid growth of private car ownership in Beijing has imposed greater loads on its road system, seriously hampering urban commuting efficiency and negatively impacting quality of life. To address such challenges and enhance the rapid development of transport infrastructure, Beijing has accelerated rail transit construction since 2008 in an effort to improve commuting capacity. This paper aims to measure time accessibility and its spatial characteristics in urban areas of Beijing by applying a comprehensive method that combines vector and raster attribute data generated from road network and subway transport infrastructure. By using a dual index of accessibility and road density, the study further reveals the features of and differences in spatial accessibility and the construction of road systems in urban areas of the northern and southern parts of Beijing. The findings of this study can provide a scientific basis for future urban planning and road system construction both in general and with respect to Beijing, given its aspirations to become a world city.

关键词：可接近性道路密度空间特征北京

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