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Hydrological Modeling of Upper OumErRabia Basin (Morocco), Comparative Study of the Event-Based and Continuous-Process HEC-HMS Model Methods
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作者 Mohamed Msaddek George Kimbowa Abdelkader El Garouani 《Computational Water, Energy, and Environmental Engineering》 2020年第4期159-184,共26页
Human population growth and land-use changes raise demand and competition for water resources. The Upper OumErRabia River Basin is experiencing high rangeland and matorral conversion to irrigated agricultural land exp... Human population growth and land-use changes raise demand and competition for water resources. The Upper OumErRabia River Basin is experiencing high rangeland and matorral conversion to irrigated agricultural land expansion. Given Morocco’s per capita water availability, River-basin hydrologic </span><span style="font-family:Verdana;">modelling</span><span style="font-family:Verdana;"> could potentially bring together agricultural, water resources </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> conservation objectives. However, not everywhere have hydrological models considered events and continuous assessment of climatic data. In this study, HEC-HMS </span><span style="font-family:Verdana;">modelling</span><span style="font-family:Verdana;"> approach is used to explore the event-based and continuous-process simulation of land-use and </span><span style="font-family:Verdana;">land cover</span><span style="font-family:Verdana;"> change (LULCC) impact on water balance. The use of HEC-GeoHMS facilitated the digital data processing for coupling with the model. The basin’s physical characteristics and the hydro-climatic data helped to generate a geospatial database for </span><span style="font-family:Verdana;">HEC-HMS</span><span style="font-family:Verdana;"> model. We analyzed baseline and future scenario changes for the 1980-2016 period using the SCS Curve-Number and the Soil Moisture Accounting (SMA) loss methods. SMA was coupled with the Hargreaves evapotranspiration method. Model calibration focused on reproducing observed basin runoff hydrograph. To evaluate the model performance for both calibration and validation</span></span><span style="font-family:Verdana;">, </span><span style="font-family:""><span style="font-family:Verdana;">the Coefficient of determination (R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">), Nash-Sutcliffe efficiency (NSE), Root Mean Square Error (RSR) </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> Percent Bias (PBIAS) criteria were exploited. The average calibration NSE values were</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.740 and 0.585 for event-based (daily) and continuous-process (annual) respectively. The R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, RSR </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> PBIAS values were 0.624, 0.634 </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> +16.7 respectively. This is rated as good performance besides the validation simulations </span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> satisfactory for subsequent hydrologic analyses. We conclude that the basin’s hydrologic response to positive and negative LULCC scenarios is significant </span><span style="font-family:Verdana;">both</span><span style="font-family:Verdana;"> positive and negative scenarios. The study findings provide useful information for key stakeholders/decision-makers in water resources. 展开更多
关键词 hec-hms model Land-Use and Land Cover Change Soil Moisture Accounting (SMA) Upper OumErRabia Watershed
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基于HEC-HMS-SVM的鄱阳湖流域平江山洪模拟研究
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作者 刘惠英 朱怀涛 吴祥宇 《水土保持研究》 北大核心 2026年第2期115-122,共8页
[目的]探究机器学习这一新方法在山洪模拟方面的应用,提高平江流域山洪模拟及早期预警精度。[方法]选取了山洪发生区1997—2018年共25场典型洪水事件及对应的5 min高分辨率降雨数据,分别构建基于HEC-HMS水文模型、支持向量机(SVM)模型及... [目的]探究机器学习这一新方法在山洪模拟方面的应用,提高平江流域山洪模拟及早期预警精度。[方法]选取了山洪发生区1997—2018年共25场典型洪水事件及对应的5 min高分辨率降雨数据,分别构建基于HEC-HMS水文模型、支持向量机(SVM)模型及HEC-HMS-SVM耦合模型,对比评估了3类模型在洪水过程模拟中的精度及稳定性。[结果](1)HEC-HMS模型对“单峰型”洪水模拟效果优异,外延性良好,整体合格率达92%(甲级精度);(2)SVM模型总体合格率为84%(乙级精度),但对峰现时间敏感性较高,率定期与验证期差异显著,稳定性较弱;(3)耦合模型综合性能最优,验证期合格率提升至100%(较SVM提高25%),整体合格率较HEC-HMS和SVM分别提高8%和16%,且洪水过程拟合度显著改善。[结论]HEC-HMS-SVM耦合模型可有效提升山洪模拟精度,为山洪灾害防治提供更可靠的技术支持。 展开更多
关键词 山洪模拟 山洪灾害 hec-hms SVM 机器学习
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基于HEC-HMS的海浪河洪水模拟研究
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作者 李港奥 刘沛显 +2 位作者 赵禹博 刘莹 贾青 《黑龙江水利科技》 2025年第8期17-21,共5页
研究以HEC-HMS水文模型为基础,对海浪河进行洪水模型的构建。经过率定和验证后,发现该模型的纳什效率系数在0.847~0.982之间,并且相对洪峰流量误差也在20%的允许范围内,模拟径流量曲线和实际径流量曲线能够很好地拟合,研究表明通过HEC-... 研究以HEC-HMS水文模型为基础,对海浪河进行洪水模型的构建。经过率定和验证后,发现该模型的纳什效率系数在0.847~0.982之间,并且相对洪峰流量误差也在20%的允许范围内,模拟径流量曲线和实际径流量曲线能够很好地拟合,研究表明通过HEC-HMS水文模型构建的海浪河流域洪水模型有良好的适用性。 展开更多
关键词 水文模型 hec-hms 海浪河流域 模拟
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HEC-HMS模型和TOPMODEL模型在东庄流域山洪预报的应用研究 被引量:15
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作者 李娟芳 王文川 +1 位作者 车沛沛 李庆敏 《水电能源科学》 北大核心 2019年第3期50-53,8,共5页
水文模型是山洪预报的理论依据,不同模型间的结构、适用性、精度均不同。为探究HEC-HMS模型和TOPMODEL模型的特性及其模拟效果的差异,选取东庄流域10场代表性洪水,以峰现时间误差、径流深误差、时间误差和确定性系数为检验指标,进行场... 水文模型是山洪预报的理论依据,不同模型间的结构、适用性、精度均不同。为探究HEC-HMS模型和TOPMODEL模型的特性及其模拟效果的差异,选取东庄流域10场代表性洪水,以峰现时间误差、径流深误差、时间误差和确定性系数为检验指标,进行场次洪水模拟。结果表明,两模型的预报方案在东庄流域模拟中各评定指标均达标,率定期均为甲等精度,验证期均为丙等精度。HEC-HMS模型和TOPMODEL模型对蒸散发的差异性参考,使得在半干旱区HEC-HMS模型的适用性更好。研究成果对于HEC-HMS模型和TOPMODEL模型在该区域的应用及防灾减灾有重要意义。 展开更多
关键词 hec-hms模型 TOPmodel模型 应用 比较 东庄流域 山洪预报
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基于HEC-HMS水文模型的老鹳河上游洪水模拟研究
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作者 冷菲雨 赵林 《水力发电》 2025年第12期32-38,75,共8页
为解决老鹳河流域洪水预报和调度问题,以米坪水文站控制流域为研究区,基于HEC-HMS水文模型,构建老鹳河上游流域洪水预报模型,采用SCS-CN径流曲线法、SCS单位线法、指数衰退法和马斯京根法进行产汇流计算与河道洪水演算。选取研究区内9... 为解决老鹳河流域洪水预报和调度问题,以米坪水文站控制流域为研究区,基于HEC-HMS水文模型,构建老鹳河上游流域洪水预报模型,采用SCS-CN径流曲线法、SCS单位线法、指数衰退法和马斯京根法进行产汇流计算与河道洪水演算。选取研究区内9场实测雨洪资料,进行模型参数率定和验证,探究模型在该流域的适用性,为流域科学优化洪水调度提供依据。结果表明:率定期6场洪水模拟合格率为83.3%,确定性系数均值为0.76;验证期3场洪水模拟合格率为100.0%,确定性系数均值为0.66。9场洪水总体预报精度达到乙级,表明HEC-HMS水文模型在老鹳河上游流域的洪水模拟中有很好的适用性,可以为该流域洪水预警提供依据。 展开更多
关键词 hec-hms模型 洪水模拟 洪水预警 参数敏感性分析 老鹳河流域
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基于HEC-HMS模型的小流域洪水预报模拟分析 被引量:1
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作者 何元翠 张健 尹树霞 《河南科技》 2025年第7期48-51,共4页
【目的】采用典型流域建模的方式,探索HEC-HMS模型在小流域的应用效果。【方法】以雪野水库流域为例,利用1963—2016年上游、茶叶口、峪门站降雨量和雪野水库入库流量,建立雪野水库流域的HEC-HMS模型,并进行模拟分析。【结果】该HEC-HM... 【目的】采用典型流域建模的方式,探索HEC-HMS模型在小流域的应用效果。【方法】以雪野水库流域为例,利用1963—2016年上游、茶叶口、峪门站降雨量和雪野水库入库流量,建立雪野水库流域的HEC-HMS模型,并进行模拟分析。【结果】该HEC-HMS模型在雪野水库流域模拟的洪水场次结果均合格,模拟效果较好;平均确定性系数为0.828,达到乙级精度。【结论】HEC-HMS模型在北方小流域的洪水预报中具有可行性。 展开更多
关键词 雪野水库流域 hec-hms 洪水预报模拟
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HEC-HMS软件在调洪计算中的应用
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作者 林春模 《水利科学与寒区工程》 2025年第2期134-137,共4页
调洪计算是水利工程设计中常规的计算,目前国内已开发了很多这方面的软件,对自由泄流的调洪计算算法比较成熟,误差较小。但是对下游有防洪任务的调洪计算相对自由泄流算法还不算多,而且调洪计算成果略有误差。HEC-HMS软件在这方面计算... 调洪计算是水利工程设计中常规的计算,目前国内已开发了很多这方面的软件,对自由泄流的调洪计算算法比较成熟,误差较小。但是对下游有防洪任务的调洪计算相对自由泄流算法还不算多,而且调洪计算成果略有误差。HEC-HMS软件在这方面计算比较成熟。 展开更多
关键词 调洪计算 控泄 hec-hms软件
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Extenuating the parameters using HEC-HMS hydrological model for ungauged catchment in the central Omo-Gibe Basin of Ethiopia
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作者 Habtamu Semunigus Demisse Abebe Temesgen Ayalew +1 位作者 Melkamu Teshome Ayana Tarun Kumar Lohani 《Journal of Groundwater Science and Engineering》 2021年第4期317-325,共9页
Characteristics of ungauged catchments can be studied from the hydrological model parameters of gauged catchments.In this research,discharge prediction was carried out in ungauged catchments using HEC-HMS in the centr... Characteristics of ungauged catchments can be studied from the hydrological model parameters of gauged catchments.In this research,discharge prediction was carried out in ungauged catchments using HEC-HMS in the central Omo-Gibe basin.Linear regression,spatial proximity,area ratio,and sub-basin mean were amalgamated for regionalization.The regional model parameters of the gauged catchment and physical characteristics of ungauged catchments were collated together to develop the equations to predict discharge from ungauged catchments.From the sensitivity analysis,crop coefficient(CC),storage coefficient(R),constant rate(CR),and time of concentration(TC)are found to be more sensitive than others.The model efficiency was evaluated using Nash-Sutcliffe Efficiency(N_(SE))which was greater than 0.75,varying between−10%and+10%and the coefficient of determination(R^(2))was approximated to be 0.8 during the calibration and validation period.The model parameters in ungauged catchments were determined using the regional model(linear regression),sub-basin mean,area ratio,and spatial proximity methods,and the discharge was simulated using the HEC-HMS model.Linear regression was used in the prediction where p-value≤0.1,determination coefficient(R2)=0.91 for crop coefficient(CC)and 0.99 for maximum deficit(MD).Constant rate(CR),maximum storage(MS),initial storage(IS),storage coefficient(R),and time of concentration(TC)were obtained.The result is that an average of 30 m^(3)/s and 15 m^(3)/s as the maximum monthly simulated flow for ungauged sub-catchments,i.e.Denchiya and Mansa of the main river basin. 展开更多
关键词 hec-hms REGIONALIZATION Stream flow simulation Ungauged catchments Omo-Gibe sub-basin
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Evaluating the Performance of HEC-HMS and SWAT Hydrological Models in Simulating the Rainfall-Runoff Process for Data Scarce Region of Ethiopian Rift Valley Lake Basin
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作者 Mohammedreshid A. Aliye Alemu O. Aga +1 位作者 Teshale Tadesse Petros Yohannes 《Open Journal of Modern Hydrology》 2020年第4期105-122,共18页
A number of physically-based and distributed watershed models have been developed to model the hydrology of the watershed. For a specific watershed, selecting the most suitable hydrological model is necessary to obtai... A number of physically-based and distributed watershed models have been developed to model the hydrology of the watershed. For a specific watershed, selecting the most suitable hydrological model is necessary to obtain good simulated results. In this study, two hydrologic models, Soil and Water Assessment Tool (SWAT) and Hydrological Engineering Centre<span style="font-family:;" "=""><span style="font-family:Verdana;">-The Hydrologic Modeling System (HEC-HMS), were applied to predict streamflow in Katar River basin, Ethiopia. The performances of these two models were compared in order to select the right model for the study basin. Both models were calibrated and validated with stream flow data of 11 years (1990-2000) and 7 years (2001-2007) respectively. Nash-Sutcliffe Error (NSE) and Coefficient of Determination (R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) were used to evaluate efficiency of the models. The results of calibration and validation indicated that, for river basin Katar, both models could simulate fairly well the streamflow. SWAT gave the model performance with the R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> > 0.78 and NSE > 0.67;and the HEC-HMS model provided the model performance with the R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> > 0.87 and NSE > 0.73. Hence, the simulated streamflow given by the HEC-HMS model is more satisfactory than that provided by the SWAT model.</span></span> 展开更多
关键词 hec-hms SWAT Katar River Basin Peak Flow Rainfall-Runoff Simulation
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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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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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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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Stability of k-ε model in Kolmogorov flow
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作者 Jiashuo GUO Le FANG 《Applied Mathematics and Mechanics(English Edition)》 2026年第1期165-184,共20页
The Reynolds-averaged Navier-Stokes(RANS)technique enables critical engineering predictions and is widely adopted.However,since this iterative computation relies on the fixed-point iteration,it may converge to unexpec... The Reynolds-averaged Navier-Stokes(RANS)technique enables critical engineering predictions and is widely adopted.However,since this iterative computation relies on the fixed-point iteration,it may converge to unexpected non-physical phase points in practice.We conduct an analysis on the phase-space characteristics and the fixed-point theory underlying the k-ε turbulence model,and employ the classical Kolmogorov flow as a framework,leveraging its direct numerical simulation(DNS)data to construct a one-dimensional(1D)system under periodic/fixed boundary conditions.The RANS results demonstrate that under periodic boundary conditions,the k-ε model exhibits only a unique trivial fixed point,with asymptotes capturing the phase portraits.The stability of this trivial fixed point is determined by a mathematically derived stability phase diagram,indicating the fact that the k-ε model will never converge to correct values under periodic conditions.In contrast,under fixed boundary conditions,the model can yield a stable non-trivial fixed point.The evolutionary mechanisms and their relationship with boundary condition settings systematically explain the inherent limitations of the k-ε model,i.e.,its deficiency in computing the flow field under periodic boundary conditions and sensitivity to boundary-value specifications under fixed boundary conditions.These conclusions are finally validated with the open-source code OpenFOAM. 展开更多
关键词 k-εmodel Kolmogorov flow INSTABILITY turbulence model
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