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基于SAM的水陆两栖环境感知微调策略与应用
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作者 左哲 蓝鸿 +1 位作者 覃卫 王坤 《北京理工大学学报》 北大核心 2026年第1期20-28,共9页
针对水陆两栖无人平台在不确定环境中面临的高误报率及多感知任务整合困难的问题,本研究提出了一种基于分割一切模型(segment anything model,SAM)的多模型联合环境感知方法,实现了障碍物检测与水陆域分割的统一处理.具体而言,是将U-Net... 针对水陆两栖无人平台在不确定环境中面临的高误报率及多感知任务整合困难的问题,本研究提出了一种基于分割一切模型(segment anything model,SAM)的多模型联合环境感知方法,实现了障碍物检测与水陆域分割的统一处理.具体而言,是将U-Net和YOLOv8与SAM结合,U-Net和YOLOv8负责获取目标的粗略轮廓,而SAM通过其编码−解码结构实现进一步精细分割.此外,设计了专门的微调策略以实现联合训练,进一步提升了模型的性能.本研究还构建了专有数据集USV-Dataset,并开发了数据引擎以提高标注效率.为增强模型的泛化能力,采用了4个公开数据集与USV-Dataset进行混合训练,涵盖了多样化的场景和障碍物类别.实验结果表明,该方法实现了96.8%的mPA分割精度和10 FPS的推理速度,展现出良好的泛化能力,能够满足中低速两栖无人平台的实时环境感知需求. 展开更多
关键词 水陆两栖平台 环境感知 sam 多模型融合
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基于SAM多尺度标签优化的半监督学习遥感目标检测 被引量:1
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作者 周洁 方振宇 《微电子学与计算机》 2026年第1期65-74,共10页
针对遥感图像中目标分辨率低、背景复杂且获取高质量旋转框标注费用高、耗时长等问题,提出了一种多尺度标签优化的半监督学习遥感目标检测方法。该方法使用SoftTeacher模型能够充分利用大量未标注且多样化的数据,同时还能发现原始数据... 针对遥感图像中目标分辨率低、背景复杂且获取高质量旋转框标注费用高、耗时长等问题,提出了一种多尺度标签优化的半监督学习遥感目标检测方法。该方法使用SoftTeacher模型能够充分利用大量未标注且多样化的数据,同时还能发现原始数据集中未标注的目标;借助SAM(Segment Anything Model)模型可实现基于深度学习的图像分割,并通过基于掩码的优化生成高质量的标签。通过半监督学习生成伪标注,对伪标注中的标签特征框进行多尺度处理后输入SAM模型进行优化,使用优化后的标注扩充原数据集样本重新用于全监督训练。实验结果表明:所选用的半监督目标检测模型SoftTeacher能够展现出优于全监督目标检测模型的性能,经过优化后的数据集样本能够展现相比原本伪标注数据集更精确的效果。在使用扩充后的数据集进行全监督训练时,原先的平均精度均值(mean Average Precision, mAP, mAP)从51.4%提升到53.5%。此外,全监督训练阶段使用现有的常用目标检测器进行了对比实验,进一步验证了所提方法可以有效提高遥感目标检测在标注不足情况下的准确性。 展开更多
关键词 遥感图像 半监督学习 sam 图像分割
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A medical image segmentation model based on SAM with an integrated local multi-scale feature encoder
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作者 DI Jing ZHU Yunlong LIANG Chan 《Journal of Measurement Science and Instrumentation》 2025年第3期359-370,共12页
Despite its remarkable performance on natural images,the segment anything model(SAM)lacks domain-specific information in medical imaging.and faces the challenge of losing local multi-scale information in the encoding ... Despite its remarkable performance on natural images,the segment anything model(SAM)lacks domain-specific information in medical imaging.and faces the challenge of losing local multi-scale information in the encoding phase.This paper presents a medical image segmentation model based on SAM with a local multi-scale feature encoder(LMSFE-SAM)to address the issues above.Firstly,based on the SAM,a local multi-scale feature encoder is introduced to improve the representation of features within local receptive field,thereby supplying the Vision Transformer(ViT)branch in SAM with enriched local multi-scale contextual information.At the same time,a multiaxial Hadamard product module(MHPM)is incorporated into the local multi-scale feature encoder in a lightweight manner to reduce the quadratic complexity and noise interference.Subsequently,a cross-branch balancing adapter is designed to balance the local and global information between the local multi-scale feature encoder and the ViT encoder in SAM.Finally,to obtain smaller input image size and to mitigate overlapping in patch embeddings,the size of the input image is reduced from 1024×1024 pixels to 256×256 pixels,and a multidimensional information adaptation component is developed,which includes feature adapters,position adapters,and channel-spatial adapters.This component effectively integrates the information from small-sized medical images into SAM,enhancing its suitability for clinical deployment.The proposed model demonstrates an average enhancement ranging from 0.0387 to 0.3191 across six objective evaluation metrics on BUSI,DDTI,and TN3K datasets compared to eight other representative image segmentation models.This significantly enhances the performance of the SAM on medical images,providing clinicians with a powerful tool in clinical diagnosis. 展开更多
关键词 segment anything model(sam) medical image segmentation ENCODER decoder multiaxial Hadamard product module(MHPM) cross-branch balancing adapter
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CSG-Net:一种融合域适应与视觉基础模型SAM的遥感影像建筑物足迹提取方法
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作者 王椰 张新长 +1 位作者 姜明 阮永俭 《测绘通报》 北大核心 2026年第3期57-61,共5页
针对深度学习建筑物足迹提取模型在跨平台与跨分辨率应用中因域间分布不一致导致的泛化能力显著下降问题,本文提出了一种跨尺度几何精炼网络(CSG-Net),构建了一个“概率-几何”串联的伪标签精炼框架,旨在提升模型在无标签目标域中的适... 针对深度学习建筑物足迹提取模型在跨平台与跨分辨率应用中因域间分布不一致导致的泛化能力显著下降问题,本文提出了一种跨尺度几何精炼网络(CSG-Net),构建了一个“概率-几何”串联的伪标签精炼框架,旨在提升模型在无标签目标域中的适应性与提取精度。首先,通过计算模型双预测分支的Jensen-Shannon散度(JSD),实现对伪标签的不确定性度量与概率加权,以软性方式抑制不可靠区域的噪声;然后,引入基于segment anything model(SAM)分割结果的几何先验,通过重叠率分析对初始伪标签的边界进行硬性几何修正,从而生成高质量的训练目标。在跨尺度建筑物提取任务上的试验表明,CSG-Net的交并比(IoU)达到73.05%,显著优于Baseline(52.49%)及其他先进域适应方法,验证了本文框架在提升跨域稳健性和提取精度方面的有效性。 展开更多
关键词 遥感影像 建筑物足迹 语义分割 域适应 segment anything model(sam)
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从通用分割到专用化建筑物提取——SAM在高分遥感影像中的优化策略研究
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作者 陈秀秀 金永胜 +1 位作者 叶建生 方雷 《中国图象图形学报》 北大核心 2026年第2期642-656,共15页
目的 针对传统高分辨率影像建筑物提取方法的精度瓶颈,SAM(segment anything model)模型虽然具有分割优势,却因训练域差异和人工提示依赖,无法直接应用于大规模遥感影像的自动化提取。为此,提出一种无提示—判别联合模型(SAM-Classifie... 目的 针对传统高分辨率影像建筑物提取方法的精度瓶颈,SAM(segment anything model)模型虽然具有分割优势,却因训练域差异和人工提示依赖,无法直接应用于大规模遥感影像的自动化提取。为此,提出一种无提示—判别联合模型(SAM-Classifier),实现了通用视觉模型向遥感场景的迁移,完成了建筑物的自动化高效提取。方法 本研究采用了一系列实验来系统探究不同提示方式(包括点提示、框提示和掩码提示)在SAM模型指导下的建筑物提取效果,并引入一个无需提示的联合模型——SAM-Classifier,以克服传统SAM模型在语义理解和提示依赖方面的限制。实验基于3个公开可用的数据集进行,以全面评估各种提示策略下SAM模型的表现。此外,为了比较不同解决方案在建筑物提取任务中的性能差异,还特别设计了对比实验,将SAM模型及SAMClassifier的结果与商汤科技开发的遥感大模型(Sense Earth 3.0)进行了详细的对比分析。结果 实验表明,框提示引导下的SAM分割表现最优(WHU数据集F1分数0.945);所提出的SAM-Classifier无需人工提示,Ma数据集F1分数0.717,与对比的先进方法性能相近。结论 本文提出SAM-Classifier,通过融合轻量级分类器实现无需提示的端到端建筑物提取,有效缓解了SAM的语义理解不足与提示依赖问题,为遥感影像的自动化解译提供了新方案。 展开更多
关键词 图像分割 高分辨率影像 建筑物提取 sam(segment anything model) 提示分割 优化策略
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基于UAV图像和SAM弱监督学习的黑土区保护性耕作玉米秸秆识别方法
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作者 赵丽华 张超 +4 位作者 王贝贝 陈畅 武亚楠 杨翠翠 李媛媛 《农业机械学报》 北大核心 2026年第3期87-96,共10页
秸秆覆盖还田是黑土区保护性耕作的重要手段,秸秆识别对于保护性耕作实施效果评估和农业管理决策具有重要意义。针对全监督深度学习秸秆遥感识别方法依赖大量像素级标注标签数据问题,提出一种基于无人机(UAV)图像和Segment anything mod... 秸秆覆盖还田是黑土区保护性耕作的重要手段,秸秆识别对于保护性耕作实施效果评估和农业管理决策具有重要意义。针对全监督深度学习秸秆遥感识别方法依赖大量像素级标注标签数据问题,提出一种基于无人机(UAV)图像和Segment anything model(SAM)的弱监督学习秸秆遥感识别方法。通过Adapter和联合损失函数对SAM进行微调,并利用边界框弱标注生成高质量伪标签,最终训练改进的U-Net分割网络实现秸秆识别。以吉林省梨树县玉米保护性耕作区为研究区进行秸秆提取试验,试验结果表明,微调后SAM的平均交并比和F1分数分别达到81.04%和87.85%,显著优于未微调模型;SAM弱监督结合改进U-Net的模型性能高于其他分割方法,F1分数为90.6%;消融试验验证了联合损失函数和卷积模块可有效提升模型性能。本文为黑土区玉米保护性耕作秸秆遥感识别提供了一种高效、低成本的解决方案。 展开更多
关键词 玉米秸秆识别 无人机图像 保护性耕作 弱监督学习 sam 语义分割
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Diff-IDS:A Network Intrusion Detection Model Based on Diffusion Model for Imbalanced Data Samples 被引量:1
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作者 Yue Yang Xiangyan Tang +3 位作者 Zhaowu Liu Jieren Cheng Haozhe Fang Cunyi Zhang 《Computers, Materials & Continua》 2025年第3期4389-4408,共20页
With the rapid development of Internet of Things technology,the sharp increase in network devices and their inherent security vulnerabilities present a stark contrast,bringing unprecedented challenges to the field of ... With the rapid development of Internet of Things technology,the sharp increase in network devices and their inherent security vulnerabilities present a stark contrast,bringing unprecedented challenges to the field of network security,especially in identifying malicious attacks.However,due to the uneven distribution of network traffic data,particularly the imbalance between attack traffic and normal traffic,as well as the imbalance between minority class attacks and majority class attacks,traditional machine learning detection algorithms have significant limitations when dealing with sparse network traffic data.To effectively tackle this challenge,we have designed a lightweight intrusion detection model based on diffusion mechanisms,named Diff-IDS,with the core objective of enhancing the model’s efficiency in parsing complex network traffic features,thereby significantly improving its detection speed and training efficiency.The model begins by finely filtering network traffic features and converting them into grayscale images,while also employing image-flipping techniques for data augmentation.Subsequently,these preprocessed images are fed into a diffusion model based on the Unet architecture for training.Once the model is trained,we fix the weights of the Unet network and propose a feature enhancement algorithm based on feature masking to further boost the model’s expressiveness.Finally,we devise an end-to-end lightweight detection strategy to streamline the model,enabling efficient lightweight detection of imbalanced samples.Our method has been subjected to multiple experimental tests on renowned network intrusion detection benchmarks,including CICIDS 2017,KDD 99,and NSL-KDD.The experimental results indicate that Diff-IDS leads in terms of detection accuracy,training efficiency,and lightweight metrics compared to the current state-of-the-art models,demonstrating exceptional detection capabilities and robustness. 展开更多
关键词 Network traffic feature enhancement diffusion model multi-classification Algorithm 2(continued)13:end for 14:Return y
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Quantitative kinetic modeling of methane generation and δ13C signals for multiple samples in closed-system pyrolysis
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作者 Zixuan Guan Wenhui Liu +1 位作者 Ping Guan Houyong Luo 《Energy Geoscience》 2025年第4期279-286,共8页
Hydrocarbon generation kinetics are influenced by complex factors,including temperature,reaction time,pressure,and molecular structure,which render simple modeling approaches inadequate for accurately simulating metha... Hydrocarbon generation kinetics are influenced by complex factors,including temperature,reaction time,pressure,and molecular structure,which render simple modeling approaches inadequate for accurately simulating methane generation.The closed-system pyrolysis experiment,a common method to study hydrocarbon generation,poses challenges for kinetic parameter regression due to limited data points.This limitation necessitates the application of sophisticated data analysis techniques to extract meaningful insights from sparse experimental data.This paper establishes a quantitative relationship between methane production and the thermal process through closed system pyrolysis experiments.A nonlinear regression model using multiple algorithms is established based on this quantitative relationship.Accordingly,a method that can quantitatively invert the methane generation kinetic parameters corresponding to the samples based on the experimental data is provided.Based on this theoretical model,a computer program capable of processing experimental data is designed and implemented.Practical analyses are performed using the method above for three samples:a coal sample from the Yulong,Guizhou;a solid bitumen sample from Guangyuan,Sichuan;and a marlstone sample containing type Ⅰ kerogen from Luquan,Yunnan.The results obtained agree with the qualitative estimates based on hydrocarbon generation kinetic theory using the previous method.Thus,the validity of the new data processing method,the new mathematical model,and the data processing procedures are verified. 展开更多
关键词 Hydrocarbon generation kinetics ISOTOPES Kinetic modeling PYROLYSIS
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A decision framework for rural domestic sewage treatment models and process:Evidence from Inner Mongolia Autonomous Region,China 被引量:1
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作者 Ying Yan Pengyu Li +5 位作者 Zixuan Wang Yubo Tan Tianlong Zheng Jianguo Liu Xiaoxia Yang Junxin Liu 《Journal of Environmental Sciences》 2026年第1期302-311,共10页
Rural domestic sewage treatment is critical for environmental protection.This study defines the spatial pattern of villages from the perspective of rural sewage treatment and develops an integrated decision-making sys... Rural domestic sewage treatment is critical for environmental protection.This study defines the spatial pattern of villages from the perspective of rural sewage treatment and develops an integrated decision-making system to propose a sewage treatment mode and scheme suitable for local conditions.By considering the village spatial layout and terrain factors,a decision tree model of residential density and terrain type was constructed with accuracies of 76.47%and 96.00%,respectively.Combined with binary classification probability unit regression,an appropriate sewage treatment mode for the village was determined with 87.00%accuracy.The Analytic Hierarchy Process(AHP),combined with the Technique for Order Preference(TOPSIS)by Similarity to an Ideal Solution model,formed the basis for optimal treatment process selection under different emission standards.Verification was conducted in 542 villages across three counties of the Inner Mongolia Autonomous Region,focusing on the standard effluent effect(0.3773),low investment cost(0.3196),and high standard effluent effect(0.5115)to determine the best treatment process for the same emission standard under different needs.The annual environmental and carbon emission benefits of sewage treatment in these villages were estimated.This model matches village density,geographic feature,and social development level,and provides scientific support and a theoretical basis for rural sewage treatment decision-making. 展开更多
关键词 Rural domestic sewage Sewage treatment model DECISION-MAKING Environmental-economic benefits Inner Mongolia
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Magnetization-resolved density of states and mixed-order transition in the two-dimensional random bond Ising model:an entropic sampling study
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作者 Yi Liu Ding Wang +2 位作者 Xin Wang Dao-Xin Yao Lei-Han Tang 《Communications in Theoretical Physics》 2025年第12期167-177,共11页
Systems with quenched disorder possess complex energy landscapes that are challenging to explore under conventional Monte Carlo methods.In this work,we implement an efficient entropy sampling scheme for accurate compu... Systems with quenched disorder possess complex energy landscapes that are challenging to explore under conventional Monte Carlo methods.In this work,we implement an efficient entropy sampling scheme for accurate computation of the entropy function in low-energy regions.The method is applied to the two-dimensional±J random-bond Ising model,where frustration is controlled by the fraction p of ferromagnetic bonds.We investigate the low-temperature paramagnetic–ferromagnetic phase boundary below the multicritical point at T_(N)=0.9530(4),P_(N)=0.89078(8),as well as the zerotemperature ferromagnetic–spin-glass transition.Finite-size scaling analysis reveals that the phase boundary for T<T_(N) exhibits reentrant behavior.By analyzing the evolution of the magnetizationresolved density of states g(E,M)and ground-state spin configurations against increasing frustration,we provide strong evidence that the zero-temperature transition is a mixed-order.Finite-size scaling conducted on the spin-glass side supports the validity of β=0,whereβis the magnetization exponent,with a correlation length exponentν=1.50(8).Our results provide new insights into the nature of the ferromagnetic-to-spin-glass phase transition in an extensively degenerate ground state. 展开更多
关键词 random bond Ising model entropic sampling mixed-order transition
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Description and Evaluation of the Emission and Atmospheric Processes Integrated and Coupled Community(EPICC)Model Version 1.0 被引量:1
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作者 EPICC Model Working Group 《Advances in Atmospheric Sciences》 2026年第4期671-694,I0001-I0006,共30页
We present a comprehensive description and benchmark evaluation of the global–regional chemical transport model called the Emission and Atmospheric Processes Integrated and Coupled Community(EPICC)model.The framework... We present a comprehensive description and benchmark evaluation of the global–regional chemical transport model called the Emission and Atmospheric Processes Integrated and Coupled Community(EPICC)model.The framework incorporates(1)grid configuration,(2)transport dynamics,(3)chemical mechanisms,(4)aerosol processes,(5)wet/dry deposition parameterizations,and(6)heterogeneous chemistry treatments associated with sulfate,nitrous acid(HONO)chemistry,and aerosol/cloud–photolysis interactions(APIs/CPIs).Openly shared with the atmospheric research community,the model facilitates integration of advanced physicochemical schemes to enhance simulation accuracy.Globally,the model demonstrates realistic representations of ozone(O_(3))and aerosol optical depth.The EPICC model generally demonstrates robust performance in simulating regional concentrations of O_(3) and PM_(2.5)(and its components)in China.It successfully captures vertical profiles of both global and regional O_(3).Notably,the model mitigates frequently reported sulfate underestimations in highly industrialized regions of China.The model accurately captures two regional severe pollution episodes observed in eastern China(January/June 2021).Sensitivity experiments highlight the critical roles of heterogeneous chemical mechanisms associated with sulfate,HONO chemistry,APIs,and CPIs in capturing PM_(2.5) and O_(3) concentrations in China.Improved sulfate mechanisms result in an increase of approximately 32.4%(2.8μg m^(−3))in simulated winter sulfate concentrations when observations exceed 10μg m^(−3).Enhanced HONO elevates winter O_(3) and PM_(2.5) by≤20 and≤10μg m^(−3),respectively.Overall,CPIs dominate over APIs in improving O_(3) and PM_(2.5) simulations across China.Locally,APIs mitigate PM_(2.5) and O_(3) discrepancies in the Sichuan Basin.Seasonal cloud–chemistry coupling explains the weaker impact of PM_(2.5) in summer. 展开更多
关键词 EPICC model PM_(2.5) O_(3) sulfate nitrous acid aerosol/cloud-photolysis interactions
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Agri-Eval:Multi-level Large Language Model Valuation Benchmark for Agriculture
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作者 WANG Yaojun GE Mingliang +2 位作者 XU Guowei ZHANG Qiyu BIE Yuhui 《农业机械学报》 北大核心 2026年第1期290-299,共10页
Model evaluation using benchmark datasets is an important method to measure the capability of large language models(LLMs)in specific domains,and it is mainly used to assess the knowledge and reasoning abilities of LLM... Model evaluation using benchmark datasets is an important method to measure the capability of large language models(LLMs)in specific domains,and it is mainly used to assess the knowledge and reasoning abilities of LLMs.Therefore,in order to better assess the capability of LLMs in the agricultural domain,Agri-Eval was proposed as a benchmark for assessing the knowledge and reasoning ability of LLMs in agriculture.The assessment dataset used in Agri-Eval covered seven major disciplines in the agricultural domain:crop science,horticulture,plant protection,animal husbandry,forest science,aquaculture science,and grass science,and contained a total of 2283 questions.Among domestic general-purpose LLMs,DeepSeek R1 performed best with an accuracy rate of 75.49%.In the realm of international general-purpose LLMs,Gemini 2.0 pro exp 0205 standed out as the top performer,achieving an accuracy rate of 74.28%.As an LLMs in agriculture vertical,Shennong V2.0 outperformed all the LLMs in China,and the answer accuracy rate of agricultural knowledge exceeded that of all the existing general-purpose LLMs.The launch of Agri-Eval helped the LLM developers to comprehensively evaluate the model's capability in the field of agriculture through a variety of tasks and tests to promote the development of the LLMs in the field of agriculture. 展开更多
关键词 large language models assessment systems agricultural knowledge agricultural datasets
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Ecological Dynamics of a Logistic Population Model with Impulsive Age-selective Harvesting
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作者 DAI Xiangjun JIAO Jianjun 《应用数学》 北大核心 2026年第1期72-79,共8页
In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy... In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting. 展开更多
关键词 The logistic population model Selective harvesting Asymptotic stability EXTINCTION
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Special Issue“Recent Developments in Dimension Reduction and Model Checking”——In Honor of Professor Lixing Zhu's Outstanding Contributions in Statistics
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作者 ZHU Liping XU Wangli LI Yingxing 《Journal of Systems Science & Complexity》 2026年第1期1-2,共2页
The proliferation of high-dimensional data and the widespread use of complex models present central challenges in contemporary statistics and data science.Dimension reduction and model checking,as two foundational pil... The proliferation of high-dimensional data and the widespread use of complex models present central challenges in contemporary statistics and data science.Dimension reduction and model checking,as two foundational pillars supporting scientific inference and data-driven decisionmaking,have evolved through the collective wisdom of generations of statisticians.This special issue,titled"Recent Developments in Dimension Reduction and Model Checking for regressions",not only aims to showcase cutting-edge advances in the field but also carries a distinct sense of academic homage to honor the groundbreaking and enduring contributions of Professor Lixing Zhu,a leading scholar whose work has profoundly shaped both areas. 展开更多
关键词 scientific inference model checking model checkingas complex models dimension reduction high dimensional data
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Ecosystem service models are indeed being validated:A response to Pereira et al.(2025)
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作者 James M.Bullock Danny A.P.Hooftman +1 位作者 John W.Redhead Simon Willcock 《Geography and Sustainability》 2026年第1期247-248,共2页
In their recent paper Pereira et al.(2025)claim that validation is overlooked in mapping and modelling of ecosystem services(ES).They state that“many studies lack critical evaluation of the results and no validation ... In their recent paper Pereira et al.(2025)claim that validation is overlooked in mapping and modelling of ecosystem services(ES).They state that“many studies lack critical evaluation of the results and no validation is provided”and that“the validation step is largely overlooked”.This assertion may have been true several years ago,for example,when Ochoa and Urbina-Cardona(2017)made a similar observation.However,there has been much work on ES model validation over the last decade. 展开更多
关键词 evaluation MAPPING modeling es model ecosystem services VALIDATION
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Efficient Model Reduction of Linear Time-varying Systems via Shifted Legendre Polynomial Approximations
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作者 XIAO Zhihua TANG Man ZHU Zhihui 《应用数学》 北大核心 2026年第2期481-493,共13页
This paper presents an efficient model reduction technique for linear time-varying systems based on shifted Legendre polynomials.The approach constructs approximate low-rank decomposition factors of finite-time Gramia... This paper presents an efficient model reduction technique for linear time-varying systems based on shifted Legendre polynomials.The approach constructs approximate low-rank decomposition factors of finite-time Gramians directly from the expansion coefficients of impulse responses.Leveraging these factors,we develop two model reduction algorithms that integrate the low-rank square root method with dominant subspace projection.Our method is computationally efficient and flexible,requiring only a few matrix-vector operations and a singular value decomposition of a low-dimensional matrix,thereby avoiding the need to solve differential Lyapunov equations.Numerical experiments confirm the effectiveness of the proposed approach. 展开更多
关键词 model reduction Time-varying systems Low-rank Gramians Balanced truncation Shifted Legendre polynomials
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Modeling of Precipitation over Africa:Progress,Challenges,and Prospects
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作者 A.A.AKINSANOLA C.N.WENHAJI +21 位作者 R.BARIMALALA P.-A.MONERIE R.D.DIXON A.T.TAMOFFO M.O.ADENIYI V.ONGOMA I.DIALLO M.GUDOSHAVA C.M.WAINWRIGHT R.JAMES K.C.SILVERIO A.FAYE S.S.NANGOMBE M.W.POKAM D.A.VONDOU N.C.G.HART I.PINTO M.KILAVI S.HAGOS E.N.RAJAGOPAL R.K.KOLLI S.JOSEPH 《Advances in Atmospheric Sciences》 2026年第1期59-86,共28页
In recent years,there has been an increasing need for climate information across diverse sectors of society.This demand has arisen from the necessity to adapt to and mitigate the impacts of climate variability and cha... In recent years,there has been an increasing need for climate information across diverse sectors of society.This demand has arisen from the necessity to adapt to and mitigate the impacts of climate variability and change.Likewise,this period has seen a significant increase in our understanding of the physical processes and mechanisms that drive precipitation and its variability across different regions of Africa.By leveraging a large volume of climate model outputs,numerous studies have investigated the model representation of African precipitation as well as underlying physical processes.These studies have assessed whether the physical processes are well depicted and whether the models are fit for informing mitigation and adaptation strategies.This paper provides a review of the progress in precipitation simulation overAfrica in state-of-the-science climate models and discusses the major issues and challenges that remain. 展开更多
关键词 RAINFALL MONSOON climate modeling CORDEX CMIP6 convection-permitting models
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基于SAM3-SEUNet模型的臂丛神经超声图像分割研究
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作者 胡杰 刘源 《电脑编程技巧与维护》 2026年第3期164-166,共3页
针对臂丛神经超声图像的噪声干扰和低对比度问题,通过提升分割性能,利用通道注意力机制优化解码器,实现了细粒度特征捕捉能力和鲁棒性的增强。研究提出了SAM3-SEUNet模型,基于SAM3编码器、集成压缩扩展适配模块、轻量解码器,并在末尾添... 针对臂丛神经超声图像的噪声干扰和低对比度问题,通过提升分割性能,利用通道注意力机制优化解码器,实现了细粒度特征捕捉能力和鲁棒性的增强。研究提出了SAM3-SEUNet模型,基于SAM3编码器、集成压缩扩展适配模块、轻量解码器,并在末尾添加SEAttention模块,支持特征融合与边缘强化。使用Kaggle Ultrasound Nerve Segmentation数据集的200张2D灰度图像进行训练,基于Py‐Torch框架、AdamW优化器,结合加权交叉熵和IoU损失,设置批量大小为12,训练50轮,采用mDice、mIoU等指标进行评估。评估结果表明,模型在噪声强、对比度低的数据集上,mDice达到0.661,mIoU达0.533,S-measure达到0.772,meanFm达到0.667,maxFm达到0.719,meanPrecision达0.710,meanRecall达到0.714,优于UNet和SAM3-UNet,展现出更好的噪声鲁棒性和边界精确性。通道注意力机制有效提升了噪声环境下的特征校准效率,预训练模型与注意力机制结合在图像分割领域潜力巨大。 展开更多
关键词 sam3-SEUNet模型 臂丛神经 超声图像分割
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Modeling reaction between high-Al steel and slag with consideration of MgO-refractory dissolution into slag
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作者 Rong-Zhen Mo Chi-Hao Zhang +1 位作者 Ying Ren Li-Feng Zhang 《Journal of Iron and Steel Research International》 2026年第3期106-115,共10页
The dissolution of MgO-refractory into the slag had an obvious influence on the steel-slag reaction and the slag property,especially for high-aluminum steels.The dissolution behavior of MgO-refractory was investigated... The dissolution of MgO-refractory into the slag had an obvious influence on the steel-slag reaction and the slag property,especially for high-aluminum steels.The dissolution behavior of MgO-refractory was investigated under various conditions,including the temperature,the initial steel composition,and the initial slag composition.A steel-slag-refractory kinetic model for high-aluminum steel was developed,which incorporated the process of MgO-refractory dissolution.The dependence of the MgO mass transfer coefficient k_(MgO)^(r)on temperature T during MgO-refractory dissolution process was established,as described by ln k_(MgO)^(r)=63,754/T+24.38524.It was indicated that the MgO dissolution rate was significantly influenced by the temperature.A higher temperature increased the dissolution rate of MgO.The initial steel composition had a slight impact on the MgO dissolution rate.Additionally,the initial slag composition strongly impacted the MgO saturation concentration and the dissolution rate.A lower initial Al_(2)O_(3)/SiO_(2)ratio increased the MgO dissolution rate.The steel-slag-refractory kinetic model accurately predicted the dissolution of MgO-refractory and the influence of dissolved MgO on the viscosity and composition change during steel-slag-refractory reactions.It was suggested that a higher temperature can hardly reduce the viscosity due to the dissolution of the MgO-refractory. 展开更多
关键词 MgO-refractory Steel-slag-refractory model Kinetic model High-aluminum steel Mold flux
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Preferences of Chinese Dermatologists for Large Language Model Responses in Clinical Psoriasis Scenarios:A Nationwide Cross-Sectional Survey in China
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作者 Jungang Yang Jingkai Xu +6 位作者 Xuejiao Song Chengxu Li Lili Chen Lingbo Bi Tingting Jiang Xianbo Zuo Yong Cui 《Health Care Science》 2026年第1期40-48,共9页
Background:Large language models(LLMs)have shown considerable promise in supporting clinical decision-making.However,their adoption and evaluation in dermatology remains limited.This study aimed to explore the prefere... Background:Large language models(LLMs)have shown considerable promise in supporting clinical decision-making.However,their adoption and evaluation in dermatology remains limited.This study aimed to explore the preferences of Chinese dermatologists regarding LLM-generated responses in clinical psoriasis scenarios and to assess how they prioritize key quality dimensions,including accuracy,traceability,and logicality.Methods:A cross-sectional,web-based survey was conducted between December 25,2024,and January 22,2025,following the Checklist for Reporting Results of Internet E-Surveys guidelines.A total of 1247 valid responses were collected from practicing dermatologists across 33 of China's provincial-level administrative divisions.Participants evaluated responses to five categories of clinical questions(etiology,clinical presentation,differential diagnosis,treatment,and case study)generated by five LLMs:ChatGPT-4o,Kimi.ai,Doubao,ZuoYiGPT,and Lingyi-agent.Statistical associations between participant characteristics and model preferences were examined using chi-square tests.Results:ChatGPT-4o(Model 1)emerged as the most preferred model across all clinical tasks,consistently receiving the highest number of votes in case study(n=740),clinical presentation(n=666),differential diagnosis(n=707),etiology(n=602),and treatment(n=656).Significant variation in model preference by professional title was observed only for the differential diagnosis task(χ^(2)=21.13,df=12,p=0.0485),while no significant differences were found across hospital tiers(p>0.05).In terms of evaluation dimensions,accuracy was most frequently rated as“very important”(n=635).A significant association existed between hospital tier and the most valued dimension(χ^(2)=27.667,df=9,p=0.0011),with dermatologists in primary hospitals prioritizing traceability more than their peers in higher-tier hospitals.No significant associations were found across professional titles(p=0.127).Conclusions:Chinese dermatologists suggest a strong preference for ChatGPT-4o over domestic LLMs in psoriasis-related clinical tasks.While accuracy remains the primary criterion,traceability and logicality are also critical,particularly for clinicians in lower-tier hospitals.These findings suggest that future clinical LLMs should prioritize not only content accuracy but also source transparency and structural clarity to meet the diverse needs of different clinical settings. 展开更多
关键词 DERMATOLOGY large language model model evaluation
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