检索结果-南通市图书馆

Assessments of Data-Driven Deep Learning Models on One-Month Predictions of Pan-Arctic Sea Ice Thickness

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第7期41卷 1379-1390页

作者： Chentao SONG Jiang zhu Xichen LI Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

In recent years,deep learning methods have gradually been applied to prediction tasks related to Arctic sea ice concentration,but relatively little research has been conducted for larger spatial and temporal scales,mainly due to the limited time coverage of observations and reanalysis ***,deep learning predictions of sea ice thickness(SIT)have yet to receive ample *** this study,two data-driven deep learning(DL)models are built based on the ConvLSTM and fully convolutional U-net(FC-Unet)algorithms and trained using CMIP6 historical simulations for transfer learning and fine-tuned using reanalysis/*** models enable monthly predictions of Arctic SIT without considering the complex physical processes *** comprehensive assessments of prediction skills by season and region,the results suggest that using a broader set of CMIP6 data for transfer learning,as well as incorporating multiple climate variables as predictors,contribute to better prediction results,although both DL models can effectively predict the spatiotemporal features of SIT *** the predicted SIT anomalies of the FC-Unet model,the spatial correlations with reanalysis reach an average level of 89%over all months,while the temporal anomaly correlation coefficients are close to unity in most *** models also demonstrate robust performances in predicting SIT and SIE during extreme *** effectiveness and reliability of the proposed deep transfer learning models in predicting Arctic SIT can facilitate more accurate pan-Arctic predictions,aiding climate change research and real-time business applications.

关键词： Arctic sea ice thickness deep learning spatiotemporal sequence prediction transfer learning

A Support Data-Based Core-Set Selection Method for Signal Recognition

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第4期21卷 151-162页

作者： Yang Ying zhu Lidong Cao Changjie National Key Laboratory of Wireless Communications(University of Electronic Science and Technology of China) Chengdu 611731China College of Computer Science and Cyber Security(Chengdu University of Technology) Chengdu 610059China College of Mathmatics and Physics(Chengdu University of Technology) Chengdu 610059China

In recent years,deep learning-based signal recognition technology has gained attention and emerged as an important approach for safeguarding the electromagnetic ***,training deep learning-based classifiers on large signal datasets with redundant samples requires significant memory and high *** paper proposes a support databased core-set selection method(SD)for signal recognition,aiming to screen a representative subset that approximates the large signal ***,this subset can be identified by employing the labeled information during the early stages of model training,as some training samples are labeled as supporting data *** support data is crucial for model training and can be found using a border sample *** results demonstrate that the SD method minimizes the impact on model recognition performance while reducing the dataset size,and outperforms five other state-of-the-art core-set selection methods when the fraction of training sample kept is less than or equal to 0.3 on the RML2016.04C dataset or 0.5 on the RML22 *** SD method is particularly helpful for signal recognition tasks with limited memory and computing resources.

关键词： core-set selection deep learning model training signal recognition support data

Carbon emission quantification and reduction in pavement use phase:A review

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2024年第1期11卷 69-91页

作者： Linjie zhu Jin Li Feipeng Xiao Key Laboratory of Road and Traffic Engineering of Ministry of Education Tongji UniversityShanghai 201804China

The carbon emissions arising from road pavement infrastructures have emerged as critical issue in recent *** life cycle of a pavement can be divided into five phases,namely raw materials and production,construction,use,maintenance and end of *** the use phase generates the highest carbon emissions throughout the pavement's life cycle,it is usually neglected in most pavement life cycle assessment(LCA)studies due to its complexity and ***,this review selected 126 relevant references,focuses on quantification methods,influential factors and reduction technologies of carbon emissions in pavement use *** the carbon accounting approached,the LCA approach,remains the most widely used for evaluating the environmental impact of ***,the primary influential factors on the use phase'carbon emission include pavement-vehicle interaction primarily affected by pavement roughness,pavement albedo and climate *** influential factors above indirectly cause changes in carbon emissions by influencing the pavement performance and subsequent vehicle ***,the review surveys carbon emission reduction technologies during pavement use phase,focusing mainly on reducing pavement rolling resistance and constructing cool *** pavements and permeable pavements are the most widely used cool pavement ***,the aspects involved in this paper hold significant promise for quantifying and reducing carbon emissions in the pavement use phase.

关键词： Pavement Carbon emission Life cycle assessment Use phase Emission reduction

Stereochemical editing:Catalytic racemization of secondary alcohols and amines

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第5期35卷 17-31页

作者： Jun Zhang Zhiyao Zheng Can zhu Department of Chemistry Fudan UniversityShanghai 200438China Department of Organic Chemistry Arrhenius LaboratoryStockholm UniversityStockholm 10691Sweden

Chiral alcohols and amines are important structural units widely existing in pharmaceuticals,agrochemicals,and food *** kinetic resolution(DKR)is an efficient strategy to deliver optically active alcohols and amines from their *** the development of DKR method,racemization catalyst plays as a crucial element with the requirement of compatibility with the kinetic resolution(KR)*** this paper,recent advance in the catalytic racemization of secondary alcohols and amines is summarized based on different types of racemizing intermediates,which are redox racemization via ketone/imine intermediates,racemization via radical intermediates,and racemization via carbocation *** racemization of secondary alcohols and amines is also enclosed.

关键词： Racemization Secondary alcohols Amines Kinetic resolution Dynamic kinetic resolution

IMAGE SUPER-RESOLUTION RECONSTRUCTION BY HUBER REGULARIZATION AND TAILORED FINITE POINT METHOD

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2024年第2期42卷 313-336页

作者： Wenli Yang Zhongyi Huang Wei zhu School of Mathematics China University of Mining and TechnologyXuzhou 221116China Department of Mathematics Tsinghua UniversityBeijing 100084China Department of Mathematics University of AlabamaTuscaloosaAL 35487USA

In this paper,we propose using the tailored finite point method(TFPM)to solve the resulting parabolic or elliptic equations when minimizing the Huber regularization based image super-resolution model using the augmented Lagrangian method(ALM).The Hu-ber regularization based image super-resolution model can ameliorate the staircase for restored *** employs the method of weighted residuals with collocation tech-nique,which helps get more accurate approximate solutions to the equations and reserve more details in restored *** compare the new schemes with the Marquina-Osher model,the image super-resolution convolutional neural network(SRCNN)and the classical interpolation methods:bilinear interpolation,nearest-neighbor interpolation and bicubic *** experiments are presented to demonstrate that with the new schemes the quality of the super-resolution images has been *** these,the existence of the minimizer of the Huber regularization based image super-resolution model and the convergence of the proposed algorithm are also established in this paper.

关键词： Image super-resolution Variational model Augmented Lagrangian methods Tailored finite point method

Spatio-temporal Evaluation of Multi-scale Cultivated Land System Resilience in Black Soil Region from 2000 to 2019:A Case Study of Liaoning Province,Northeast China

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

Chinese Geographical Science 2024年第1期34卷 168-180页

作者： WANG Yue JIANG Yuting zhu Guoxu School of Management Shenyang Normal UniversityShenyang110034China Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun130012China

It is of great significance to systematically analyze the cultivated land system resilience(CLSR) for the black soil protection and national food *** CLSR is impacted by planting structure adjustment and cultivated land quality decline,posing major hidden dangers to food *** is urgent to evaluate the CLSR at multiple spatio-temporal *** study took Liaoning Province in the black soil region of Northeast China as an *** on the resilience theory,this study constructed the CLSR evaluation system from the input-feedback perspective at the provincial-scale and the city-scale,and used the rank-sum ratio comprehensive evaluation method(RSR) to analyze the key influencing factors of CLSR in Liaoning Province and its 14 cities from 2000 to *** results showed that:1) the time series changes of CLSR at the provincial-scale and the city-scale in Liaoning Province were similar,both showing an increasing trend.2) The CLSR in Liaoning Province presented a spatial pattern of ‘high in the west and low in the east’ at the city-scale.3) There were seven and six main influencing factors of CLSR at the provincial-scale and the city-scale,*** addition to the net income per capita of rural households,other influencing factors of CLSR were different at the provincial-scale and the *** feedback factors were dominant at the provincial-scale,and the input factors and feedback factors were dominant at the *** results could provide a reference for the utilization of black soil and draw on the experience of regional agricultural planning and adjustment.

关键词： cultivated land system resilience(CLSR) rank-sum ratio comprehensive evaluation(RSR) multi-scales influencing factors black soil region Liaoning Province,China

Global practical stabilization of the double integrator system with an imperfect sensor and subject to a bounded disturbance

在线全文

学校读者我要写书评

暂无评论

Control Theory and Technology 2024年第3期22卷 468-478页

作者： Zhiyuan zhu Yuanlong Li Zongli Lin Department of Automation Shanghai Jiao Tong Universityand Key Laboratory of System Control and Information Processing of Ministry of EducationShanghai 200240China Charles L.Brown Department of Electrical and Computer Engineering University of VirginiaP.0.Box 400743CharlottesvilleVA 22904-4743USA

This paper is concerned with global practical stabilization of the double integrator system with an imperfect sensor and subject to an additive bounded output *** imperfect sensor nonlinearity possesses the nonlinear characteristics of saturation and dead *** of the presence of output dead zone and the additive disturbance,the states cannot be expected to driven into an arbitrarily small neighborhood of the *** solve the global practical stabilization problem,we proposes a low gain-based linear dynamic output feedback law,under which the first state enters and remains in a bounded set whose size is depended on the bound of disturbance and the range of dead zone and the second state enters and remains in a pre-specified arbitrarily small set,both in finite *** results illustrate the effectiveness of our proposed control method.

关键词： Output saturation Disturbance rejection Output dead zone Low gain feedback-Linear output feedback Practical stabilization

For LEO Satellite Networks: Intelligent Interference Sensing and Signal Reconstruction Based on Blind Separation Technology

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

China Communications 2024年第2期21卷 85-95页

作者： Chengjie Li Lidong zhu Zhen Zhang The Key Laboratory for Computer Systems of State Ethnic Affairs Commission School of Computer Science and Technology(Southwest Minzu University)Chengdu 610000China National Key Laboratory of Science and Technology on Communications(University of Electronic Science and Technology of China) Chengdu 610000China College of Computer Science(Sichuan University) Chengdu 610000China

In LEO satellite communication networks,the number of satellites has increased sharply, the relative velocity of satellites is very fast, then electronic signal aliasing occurs from time to time. Those aliasing signals make the receiving ability of the signal receiver worse, the signal processing ability weaker,and the anti-interference ability of the communication system lower. Aiming at the above problems, to save communication resources and improve communication efficiency, and considering the irregularity of interference signals, the underdetermined blind separation technology can effectively deal with the problem of interference sensing and signal reconstruction in this scenario. In order to improve the stability of source signal separation and the security of information transmission, a greedy optimization algorithm can be executed. At the same time, to improve network information transmission efficiency and prevent algorithms from getting trapped in local optima, delete low-energy points during each iteration process. Ultimately, simulation experiments validate that the algorithm presented in this paper enhances both the transmission efficiency of the network transmission system and the security of the communication system, achieving the process of interference sensing and signal reconstruction in the LEO satellite communication system.

关键词： blind source separation greedy optimization algorithm interference sensing LEO satellite communication networks signal reconstruction

Vector Radiative Transfer in a Vertically Inhomogeneous Scattering and Emitting ***Ⅰ:A New Discrete Ordinate Method

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2024年第2期38卷 209-224页

作者： Ziqiang zhu Fuzhong WENG Yang HAN Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081 University of Chinese Academy of Sciences Beijing 100049 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

The original vector discrete ordinate radiative transfer(VDISORT)model takes into account Stokes radiance vector but derives its solution assuming azimuthal symmetric surface reflective matrix and atmospheric scattering phase matrix,such as the phase matrix derived from spherical particles or randomly oriented non-spherical *** this study,a new VDISORT is developed for general atmospheric scattering and boundary *** vector is decomposed into both sinusoidal and cosinusoidal harmonic modes,and the radiance at arbitrary viewing geometry is solved directly by adding two zero-weighted points in the Gaussian quadrature *** complex eigenvalues in homogeneous solutions are also taken into full *** accuracy of VDISORT model is comprehensively validated by four cases:Rayleigh scattering case,the spherical particle scattering case with the Legendre expansion coefficients of 0th-13th orders of the phase matrix(hereinafter L13),L13 with a polarized source,and the randomoriented oblate particle scattering case with the Legendre expansion coefficients of 0th-11th orders of the phase matrix(hereinafter L11).In all cases,the simulated radiances agree well with the benchmarks,with absolute biases less than 0.0065,0.0006,and 0.0008 for Rayleigh,unpolarized L13,and L11,*** a polarized bidirectional reflection distribution function(pBRDF)matrix is used as the lower boundary condition,VDISORT is now able to handle fully coupled atmospheric and surface polarimetric radiative transfer processes.

关键词： radiative transfer discrete ordinate polarization Stokes vector vector discrete ordinate radiative transfer(VDISORT)