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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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A comprehensive assessment and analysis of Antarctic satellite grounding line products from 1992 to 2009

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Science China Earth Sciences 2021年第10期64卷 1332-1345页

作者： Rongxing LI Da LV Huan XIE yixiang tian Yang XU Saisai LU Xiaohua TONG Hexia WENG Center for Spatial Information Science and Sustainable Development and Applications Tongji UniversityShanghai 200092China College of Surveying and Geo-Informatics Tongji UniversityShanghai 200092China

In this paper,we present the results of a comprehensive assessment and analysis of five major Antarctic grounding line(GL)products from remote sensing *** systematic assessment of this large amount of GL data was performed using a new two-step framework and implementation strategy,in which 84.4%of the product data were processed effectively by using a set of developed assessment metrics,with the remaining 15.6%handled by a comprehensive manual processing procedure aided by additional multisource *** radar GL product shows a high quality(inconsistency of 0.3%)and is recommended for use wherever ***,the optical image GL products show a lower quality(inconsistency of 3-12%)but offer complete coverage,particularly in areas of weak *** GL analysis based on the assessed products(1992–2009)showed that 9.5%of the entire Antarctic GL were retreating or advancing,classified as a dynamic *** the basin scale,the highest retreat rate was−1544±51 m a^(-1) in Basin 22(including Pine Island Glacier)and the highest advancement rate was 304±16 m a^(-1) in Basin 14(including Mertz Glacier).The West Antarctic Ice Sheet(WAIS)and the East Antarctic Ice Sheet(EAIS)showed the average GL change rates of−370±8 m a^(-1) and 5±7 m a^(-1),respectively,indicating that there was a clear trend of GL retreat in WAIS and a balanced to slightly advanced GL state in EAIS(except for the region around Totten).

关键词： Grounding line products Assessment Antarctic Ice shelves

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基于演化博弈的中国绿色债券评级评估系统激励与约束机制研究

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金融理论与实践 2023年第3期 11-23页

作者：赵涵亦田益祥电子科技大学经济与管理学院四川成都611731

引入政府财政激励与证监会监管约束条件,基于演化博弈理论构建绿色债券评级评估机制四位参与者的2*2策略互动支付矩阵,并运用数值仿真分析绿色债券评级评估系统下财政激励、监管约束政策减少评估“漂绿”与评级“虚高”情形的适用条件... 详细信息

引入政府财政激励与证监会监管约束条件,基于演化博弈理论构建绿色债券评级评估机制四位参与者的2*2策略互动支付矩阵,并运用数值仿真分析绿色债券评级评估系统下财政激励、监管约束政策减少评估“漂绿”与评级“虚高”情形的适用条件。研究表明:绿色债券发展初期,提升政府财政激励在一定条件下能够提高评估评级机构选择绿色债券公正评估评级的概率,但会增加监管成本;提升监管惩罚约束在一定条件下能够防范评级评估机构做出“漂绿”评估和“虚高”评级并降低监管成本;在财政激励一定时,提高监管惩罚约束中的不定期监督检查频率为绿色债券评级评估有效性带来的正向影响比加大监管惩罚力度更为显著。研究结论为监管者和政府选择合适的激励约束政策提供了管理建议。

关键词：绿色债券信用评级监管第三方绿色评估认证演化博弈

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一类Lagrange 系统的PSM 问题(英文)

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控制理论与应用 1999年第6期16卷 848-852页

作者：田益祥武汉冶金科技大学管理二系武汉430070

ＰＳＭ思想在［１］中第一次提出，得到了广泛的应用．本文根据ＰＳＭ思想，建立一个特殊模型，在非线性系统中研究拉格朗日系统的ＰＳＭ，解决了模型的ＰＳＭ

关键词： Lagrange系统 PSM问题非线性系统

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Searching Multiple Structural Changes of Chinese Stock Market via GMDH

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Journal of Systems Science and Information 2009年第3期7卷 193-200页

作者： yixiang tian Li Zhou School of Management UESTC Chengdu 610054 China Chongqing Radio ＆ TV University Chongqing 400052 China

This paper analyzes multiple structural changes by GMDH (Group Methods of Data Handling), which have obvious advantages. Our method extends the model of Lumsdaine & Papell (1997), and it could be applied to the case of more than two structural changes. Because of simultaneously considering every structural change of the hypothesis, it is likely to be of particular relevance in practice. And it can decrease large investigation costs by MATLAB programming. What is more, we can select the criterion value of F incremental statistic to control the significance of the breaks, based on kinds of investigation intentions. And the empirical evidences on Shenzhen Composite Index are presented to illustrate the usefulness of our method.

关键词：中国股票市场自组织多重结构消耗臭氧层物质搜索数据处理多结构

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A Blockchain-Based Access Control Scheme for Reputation Value Attributes of the Internet of Things

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Computers, Materials & Continua 2024年第1期78卷 1297-1310页

作者： Hongliang tian Junyuan tian College of Electrical Engineering Northeast Electric Power UniversityJilin132012China

The Internet of Things(IoT)access controlmechanism may encounter security issues such as single point of failure and data *** address these issues,a blockchain-based IoT reputation value attribute access control scheme is ***,writing the reputation value as an attribute into the access control policy,and then deploying the access control policy in the smart contract of the blockchain system can enable the system to provide more fine-grained access control;Secondly,storing a large amount of resources fromthe Internet of Things in Inter Planetary File System(IPFS)to improve system throughput;Finally,map resource access operations to qualification tokens to improve the performance of the access control *** simulation experiments based on the Hyperledger Fabric *** simulation experimental results,it can be seen that the access control system can achieve more fine-grained and dynamic access control while maintaining high throughput and low time delay,providing sufficient reliability and security for access control of IoT devices.

关键词： Blockchain IoT access control Hyperledger Fabric

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Transformer and GAN-Based Super-Resolution Reconstruction Network for Medical Images

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Tsinghua Science and Technology 2024年第1期29卷 197-206页

作者： Weizhi Du Shihao tian Arts&Sciences College Washington University in St.LouisSt.LouisMO 63130USA Department of Electric and Computing Engineering Cornell UniversityIthacaNY 14850USA

Super-resolution reconstruction in medical imaging has become more demanding due to the necessity of obtaining high-quality images with minimal radiation dose,such as in low-field magnetic resonance imaging(MRI).However,image super-resolution reconstruction remains a difficult task because of the complexity and high textual requirements for diagnosis *** this paper,we offer a deep learning based strategy for reconstructing medical images from low resolutions utilizing Transformer and generative adversarial networks(T-GANs).The integrated system can extract more precise texture information and focus more on important locations through global image matching after successfully inserting Transformer into the generative adversarial network for picture ***,we weighted the combination of content loss,adversarial loss,and adversarial feature loss as the final multi-task loss function during the training of our proposed model *** comparison to established measures like peak signal-to-noise ratio(PSNR)and structural similarity index measure(SSIM),our suggested T-GAN achieves optimal performance and recovers more texture features in super-resolution reconstruction of MRI scanned images of the knees and belly.

关键词： super-resolution image reconstruction Transformer generative adversarial network(GAN)

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Robust adaptive radar beamforming based on iterative training sample selection using kurtosis of generalized inner product statistics

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Journal of Systems Engineering and Electronics 2024年第1期35卷 24-30页

作者： tian Jing ZHANG Wei School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Electromagnetic Space Security Chengdu 610036China

In engineering application,there is only one adaptive weights estimated by most of traditional early warning radars for adaptive interference suppression in a pulse reputation interval(PRI).Therefore,if the training samples used to calculate the weight vector does not contain the jamming,then the jamming cannot be removed by adaptive spatial *** the weight vector is constantly updated in the range dimension,the training data may contain target echo signals,resulting in signal cancellation *** cope with the situation that the training samples are contaminated by target signal,an iterative training sample selection method based on non-homogeneous detector(NHD)is proposed in this paper for updating the weight vector in entire range *** principle is presented,and the validity is proven by simulation results.

关键词： adaptive radar beamforming training sample selection non-homogeneous detector electronic jamming jamming suppression

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DeepSI:A Sensitive-Driven Testing Samples Generation Method of Whitebox CNN Model for Edge Computing

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Tsinghua Science and Technology 2024年第3期29卷 784-794页

作者： Zhichao Lian Fengjun tian School of Cyber Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China

In recent years,Deep Learning(DL)technique has been widely used in Internet of Things(IoT)and Industrial Internet of Things(IIoT)for edge computing,and achieved good *** more and more studies have shown the vulnerability of neural ***,it is important to test the robustness and vulnerability of neural *** specifically,inspired by layer-wise relevance propagation and neural network verification,we propose a novel measurement of sensitive neurons and important neurons,and propose a novel neuron coverage criterion for robustness *** on the novel criterion,we design a novel testing sample generation method,named DeepSI,which involves definitions of sensitive neurons and important ***,we construct sensitive-decision paths of the neural network through selecting sensitive neurons and important ***,we verify our idea by setting up several experiments,then results show our proposed method achieves superior performances.

关键词： neuron sensitivity Layer-wise Relevance Propagation(LRP) neural network verification deeplearning testing

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Frequency Domain Fatigue Evaluation on SCR Girth-Weld Based on Structural Stress

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China Ocean Engineering 2024年第2期38卷 255-270页

作者： ZHANG Long ZHAO tian-feng College of Safety and Ocean Engineering China University of Petroleum(Beijing)Beijing 102249China

The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating *** harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue *** structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue ***,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural ***,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into *** research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.

关键词： SCR girth weld random vibration self(cross)power spectrum structural stress method biaxial fatigue damage

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