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Machine learning based models for predicting compressive strength of geopolymer concrete

Frontiers of Structural and Civil Engineering 2024年第7期18卷 1028-1049页

作者： Quang-Huy LE Duy-hung NGUYEN Thanh SANG-TO Samir KHATIR Hoang LE-MINH Amir H.GANDOMI Thanh CUONG-LE Center for Engineering Application and Technology Solutions Ho Chi Minh City Open UniversityHo Chi Minh 700000Vietnam Institute of Civil Engineering Ho Chi Minh City University of TransportHo Chi Minh 700000Vietnam Faculty of Engineering&Information Technology University of Technology SydneyUltimoNSW 2007Australia

Recently,great attention has been paid to geopolymer concrete due to its advantageous mechanical and environmentally friendly *** effort has been made in experimental studies to advance the understanding of geopolymer concrete,in which compressive strength is one of the most important *** facilitate engineering work on the material,an efficient predicting model is *** this study,three machine learning(ML)-based models,namely deep neural network(DNN),K-nearest neighbors(KNN),and support vector machines(SVM),are developed for forecasting the compressive strength of the geopolymer concrete.A total of 375 experimental samples are collected from the literature to build a database for the development of the predicting models.A careful procedure for data preprocessing is implemented,by which outliers are examined and removed from the database and input variables are standardized before feeding to the fitting *** standard K-fold cross-validation approach is applied for evaluating the performance of the models so that overfitting status is well managed,thus the generalizability of the models is *** effectiveness of the models is assessed via statistical metrics including root mean squared error(RMSE),mean absolute error(MAE),correlation coefficient(R),and the recently proposed performance index(PI).The basic mean square error(MSE)is used as the loss function to be minimized during the model fitting *** three ML-based models are successfully developed for estimating the compressive strength,for which good correlations between the predicted and the true values are obtained for DNN,KNN,and *** numerical results suggest that the DNN model generally outperforms the other two models.

关键词： geopolymer concrete compressive strength prediction machine-learning based model deep neural network K-nearest neighbor support vector machines

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城乡融合发展的内在逻辑与现实选择

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行政管理改革 2024年第4期 54-63页

作者：黄锟吉伟伦中共中央党校(国家行政学院)中国式现代化研究中心中共中央党校(国家行政学院)马克思主义学院当代资本主义研究所中共中央党校(国家行政学院)公共管理教研部

新时代城乡融合发展是深入推进中国式现代化,实现第二个百年奋斗目标的战略举措,但在长期发展过程中,城乡间部分要素的单向流动问题仍有优化空间,实现要素双向流动的目标依旧任重道远。当前,在城乡融合发展中,在人口、资金、生态和公共... 详细信息

新时代城乡融合发展是深入推进中国式现代化,实现第二个百年奋斗目标的战略举措,但在长期发展过程中,城乡间部分要素的单向流动问题仍有优化空间,实现要素双向流动的目标依旧任重道远。当前,在城乡融合发展中,在人口、资金、生态和公共服务要素流动中还存在一定困境,未来,将“以人才为中心”“以金融为动力”“以生态为切入口”“以公共服务为基点”,破解城乡要素流动困境、促进城乡融合发展。

关键词：城乡融合内在逻辑实现路径城乡要素流动

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Inter-layer interference for multi-layered tight gas reservoir in the absence and presence of movable water

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Petroleum Science 2024年第3期21卷 1751-1764页

作者： Tao Zhang Bin-Rui Wang Yu-Long Zhao Lie-Hui Zhang Xiang-Yang Qiao Lei Zhang Jing-Jing Guo hung Vo Thanh National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu60500SichuanChina Shaanxi Yanchang Petroleum(Group)Corp.Ltd. Xian710075ShaanxiChina Waseda Research Institute for Science and Engineering Waseda UniversityTokyoJapan

Due to the dissimilarity among different producing layers,the influences of inter-layer interference on the production performance of a multi-layer gas reservoir are ***,systematic studies of inter-layer interference for tight gas reservoirs are really limited,especially for those reservoirs in the presence of *** this work,five types of possible inter-layer interferences,including both absence and presence of water,are identified for commingled production of tight gas ***,a series of reservoir-scale and pore-scale numerical simulations are conducted to quantify the degree of influence of each type of *** field evidence from the Yan'an tight gas reservoir(Ordos Basin,China)is found to support the simulation ***,suggestions are proposed to mitigate the potential inter-layer *** results indicate that,in the absence of water,commingled production is favorable in two situations:when there is a difference in physical properties and when there is a difference in the pressure system of each *** reservoirs with a multi-pressure system,the backflow phenomenon,which significantly influences the production performance,only occurs under extreme conditions(such as very low production rates or well shut-in periods).When water is introduced into the multi-layer system,inter-layer interference becomes nearly *** both the gas-rich layer and water-rich layer for commingled production is not desirable,as it can trigger water invasion from the water-rich layer into the gas-rich *** gas-rich layer might also be interfered with by water from the neighboring unperforated water-rich layer,where the water might break the barrier(eg weak joint surface,cement in fractures)between the two layers and migrate into the gas-rich ***,the gas-rich layer could possibly be interfered with by water that accumulates at the bottom of the wellbore due to gravitational diff

关键词： Tight gas Comingled production Interference Two-phase flow Water blocking

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The mediatory role of water quality on the association between extreme precipitation events and infectious diarrhea in the Yangtze River Basin,China

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Fundamental Research 2024年第3期4卷 495-504页

作者： Junfeng Yu Liang Zhao Xin-Zhong Liang hung Chak Ho Masahiro Hashizume Cunrui Huang School of Public Health Sun Yat-sen UniversityGuangzhou 510080China The State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Department of Atmospheric and Oceanic Science University of MarylandCollege ParkMD 20740USA Department of Public and International Affairs City University of Hong KongHong Kong 999077China Department of Global Health Policy Graduate School of MedicineThe University of TokyoTokyo 113-0033Japan Vanke School of Public Health Tsinghua UniversityBeijing 100084China Institute of Healthy China Tsinghua UniversityBeijing 100084China

Extreme precipitation is exacerbating the burden of infectious diarrhea in the context of climate change,it is necessary to identify the critical and easy-to-intervene intermediate factors for public health *** quality may be the most important mediator,while relevant empirical evidence is *** study aimed to examine the role of water quality in the process of infectious diarrhea caused by extreme *** infectious diarrhea cases,meteorological factors and water quality data in Yangtze River Basin in China between October 29,2007 to February 19,2017 were ***-stage statistical models were used to estimate city-specific extreme precipitation,water quality and infectious diarrhea relationships that were pooled to derive regional estimates.A causal mediation analysis was used to assess the mediation effect of water *** Yangtze River Basin,extreme precipitation events had a significant impact on infectious diarrhea(Incidence Rate Ratios[IRR]:1.027,95%Confidence Interval[CI]:1.013~1.041).After extreme precipitation events,the dissolved oxygen(DO)in surface water decreased(-0.123 mg/L,95%CI:-0.159 mg/L~-0.086 mg/L),while the un-ionized ammonia(NH(3)-N)increased(0.004 mg/L,95%CI:0.001 mg/L~0.006 mg/L).The combined overall effect of DO and NH(3)-N on infectious diarrhea showed that both low and high concentrations were associated with an increased risk of infectious *** causal mediation analysis showed that the mediation proportion of the two water quality indexes(DO and NH(3)-N)is 70.54%(P<0.001).To reduce the health effects of extreme precipitation,in contrast to current population-oriented health strategies,those that take into account more direct and easy-to-intervene water quality indicators should be encouraged by future policies.

关键词： Extreme precipitation Infectious diarrhea Water quality Dissolved oxygen Un-ionized ammonia Mediation analysis

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高度取向磷酸锆/环氧树脂纳米复合涂层的防腐蚀性能

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高分子材料科学与工程 2024年第4期40卷 72-78页

作者：雷凡冯民生李涛 hung-Jue Sue 李姜成都大学机械工程学院四川成都610106 Polymer Technology Center Department of Materials Science and EngineeringTexas A&M UniversityCollege StationTX 77843-3123USA 高分子材料工程国家重点实验室(四川大学)四川大学高分子研究所四川成都610065

针对金属防腐蚀的需求,采用简单的喷涂法在金属基底上制备了高度取向磷酸锆/环氧树脂纳米复合涂层。利用透射电镜和X射线衍射分析探究了复合涂层中磷酸锆纳米粒子的分散形貌,采用电化学交流阻抗谱和动电位极化曲线等测试评价了复合涂层... 详细信息

针对金属防腐蚀的需求,采用简单的喷涂法在金属基底上制备了高度取向磷酸锆/环氧树脂纳米复合涂层。利用透射电镜和X射线衍射分析探究了复合涂层中磷酸锆纳米粒子的分散形貌,采用电化学交流阻抗谱和动电位极化曲线等测试评价了复合涂层的防腐蚀性能和其作用机理。结果表明,高度取向的磷酸锆纳米粒子可有效地增加水、氧气、电解液的扩散路径,改善涂层的防腐蚀性能。此外,该绝缘涂层也可进一步阻止腐蚀介质的迁移,增加涂层电阻,显著提高环氧树脂涂层对金属基底的长期防护性能。

关键词：环氧树脂磷酸锆高度取向防腐蚀性能

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多模态高精度非线性激活函数协处理器设计

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计算机辅助设计与图形学学报 2024年第4期36卷 598-606页

作者：欧文辉王峥吴卓宇王伟伦甘志银华中科技大学武汉光电国家研究中心武汉430074 中国科学院深圳先进技术研究院异构智能计算中心深圳518055 中科元物芯科技有限公司深圳518066 Department of Engineering Durham University Durham DH13LE UK

针对片上部署非线性激活函数产生的精度损失以及硬件资源开销大的问题,提出一种基于三分法指数方法的多模态高精度非线性激活函数协处理器设计.首先分析激活函数在不同拟合参数下的近似误差以及运算量,为设计提供指导;然后设计一种模块... 详细信息

针对片上部署非线性激活函数产生的精度损失以及硬件资源开销大的问题,提出一种基于三分法指数方法的多模态高精度非线性激活函数协处理器设计.首先分析激活函数在不同拟合参数下的近似误差以及运算量,为设计提供指导;然后设计一种模块化的硬件框架,通过复用指数、对数、sigmoid模块并结合浮点计算单元,能够以较低的面积开销部署多种激活函数.在Xilinx的Vertix系列FPGA上完成原型测试,实验结果表明,在仅增加32个查找表的情况下,所提设计tanh和sigmoid的近似误差仅为2项拆分指数方法的65.02%和69.00%,同时拟合范围扩大60%;与高精度分段线性逼近方法相比,该设计在仅用4%的查找表数量的情况下,将近似误差缩小82%.

关键词：非线性激活函数神经网络数学拟合 FPGA

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未知环境下无人机集群智能协同探索路径规划

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工程科学学报 2024年第7期46卷 1197-1206页

作者：王伟伦尤明孙磊张秀云宗群天津大学电气自动化与信息工程学院天津300072 沈阳飞机设计研究所沈阳110035 陆军航空兵研究所北京101100

随着无人机执行任务复杂性与环境种类多样性的不断提高,多无人机集群系统逐渐得到国内外的广泛关注,无人机路径规划成为当前研究热点.考虑到传统路径规划算法一般需要先验地图信息,在搜索救援等环境未知场景中难以满足,本文提出了一种... 详细信息

随着无人机执行任务复杂性与环境种类多样性的不断提高,多无人机集群系统逐渐得到国内外的广泛关注,无人机路径规划成为当前研究热点.考虑到传统路径规划算法一般需要先验地图信息,在搜索救援等环境未知场景中难以满足,本文提出了一种基于强化学习的未知环境下的无人机集群协同探索路径规划方法.首先,考虑无人机集群协同探索任务特点及动力学、避碰避障等约束条件,基于马尔可夫决策过程,建立无人机集群协同探索博弈模型与评价准则.其次,提出基于强化学习方法的无人机集群协同探索方法,建立基于策略-评判网络的双网络架构,并利用随机地图增强探索方法面对未知环境的泛化能力.每架无人机在探索过程中不断收集地图信息,并基于环境信息和个体间的共享信息调整自身策略,通过迭代训练实现未知环境下的集群协同探索.最后,基于Unity搭建无人机集群协同探索虚拟仿真平台,并与非合作的单智能体算法进行对比试验,验证了本文所提算法在任务成功率、任务完成效率和回合奖励等方面均具有优势.

关键词：无人机集群深度强化学习自主探索路径规划

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Role of metabolic dysfunction and inflammation along the liver-brain axis in animal models with obesity-induced neurodegeneration

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Neural Regeneration Research 2025年第4期20卷 1069-1076页

作者： Evridiki Asimakidou Eka Norfaishanty Saipuljumri Chih hung Lo Jialiu Zeng Department of Clinical Neurosciences University of CambridgeCambridgeUK School of Applied Science Republic PolytechnicSingaporeSingapore Lee Kong Chian School of Medicine Nanyang Technological UniversitySingaporeSingapore

The interaction between metabolic dysfunction and inflammation is central to the development of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s ***-related conditions like type 2 diabetes and non-alcoholic fatty liver disease exacerbate this *** lipid accumulation,particularly in the liver,initiates a cascade of inflammatory processes that extend to the brain,influencing critical metabolic regulatory *** and palmitate,key lipid components,along with lipid transporters lipocalin-2 and apolipoprotein E,contribute to neuroinflammation by disrupting blood–brain barrier integrity and promoting *** insulin resistance further exacerbates brain insulin resistance and *** interventions targeting peripheral lipid metabolism and insulin signaling pathways have shown promise in reducing neuroinflammation in animal ***,translating these findings to clinical practice requires further investigation into human *** conclusion,metabolic dysfunction,peripheral inflammation,and insulin resistance are integral to neuroinflammation and *** these complex mechanisms holds potential for identifying novel therapeutic targets and improving outcomes for neurodegenerative diseases.

关键词： Alzheimer’s disease inflammatory cytokines insulin resistance lipid

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基于分子动力学方法的石墨烯/聚乙烯复合材料界面剪切力学性能的研究

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功能材料 2024年第5期55卷 5188-5194页

作者：罗伟伦苏广厦黄立新广西大学土木建筑工程学院南宁530004 广西大学工程防灾与结构安全教育部重点实验室南宁530004

采用分子动力学模拟的方法进行石墨烯/聚乙烯复合材料界面剪切力学性能的研究。首先建立石墨烯/聚乙烯复合材料分子动力学模拟计算的模型,然后在300 K温度下对石墨烯进行了拉拔模拟实验,探讨石墨烯倾斜角度和层数对复合材料界面剪切力... 详细信息

采用分子动力学模拟的方法进行石墨烯/聚乙烯复合材料界面剪切力学性能的研究。首先建立石墨烯/聚乙烯复合材料分子动力学模拟计算的模型,然后在300 K温度下对石墨烯进行了拉拔模拟实验,探讨石墨烯倾斜角度和层数对复合材料界面剪切力学性能的影响。模拟计算结果表明,在拔出速率为0.001 nm/fs的情况下,石墨烯25°倾斜角模型的界面剪切强度最大,比0°倾斜角模型界面剪切强度增加了39.8%,可见石墨烯倾斜角对界面剪切强度有较大的影响。在拔出速率为0.001 nm/fs和石墨烯0°倾斜角的情况下,单层、双层和三层石墨烯的聚乙烯复合材料模型的界面剪应力最大值分别为89.20、114.21和129.28 MPa,显然增加石墨烯层数能显著提高复合材料的界面剪切性能。当拔出速率为0.0005 nm/fs时,单层、双层和三层石墨烯的聚乙烯复合材料模型的剪切强度值比较接近,随着速率增加到0.001 nm/fs,三层模型剪切强度增强最大,双层模型次之,单层模型最小,然而速率超过0.001 nm/fs之后,单层模型剪切强度几乎线性增强,双层和三层模型剪切强度增强的幅度均比单层模型小,这说明拔出速率的增加使得复合材料的界面剪切强度呈现较大的提高。

关键词：分子动力学方法石墨烯聚乙烯复合材料界面剪切力学性能

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Automatic fovea detection and choroid segmentation for choroidal thickness assessment in optical coherence tomography

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International Journal of Ophthalmology(English edition) 2024年第10期17卷 1763-1771页

作者： Chen Yu Lin hung Ju Chen Yi Kit Chan Wei Ping Hsia Yu Len Huang Chia Jen Chang Department of Ophthalmology Taichung Veterans General HospitalTaichung 407TaiwanChina Department of Computer Science Tunghai UniversityTaichung 407TaiwanChina

AIM:To develop an automated model for subfoveal choroidal thickness(SFCT)detection in optical coherence tomography(OCT)images,addressing manual fovea location and choroidal contour ***:Two procedures were proposed:defining the fovea and segmenting the *** localization from B-scan OCT image sequence with three-dimensional reconstruction(LocBscan-3D)predicted fovea location using central foveal depression features,and fovea localization from two-dimensional en-face OCT(LocEN-2D)used a mask region-based convolutional neural network(Mask R-CNN)model for optic disc detection,and determined the fovea location based on optic disc relative *** segmentation also employed Mask ***:For 53 eyes in 28 healthy subjects,LocBscan-3D’s mean difference between manual and predicted fovea locations was 170.0μm,LocEN-2D yielded 675.9μ***-2D performed better in non-high myopia group(P=0.02).SFCT measurements from Mask R-CNN aligned with manual ***:Our models accurately predict SFCT in OCT ***-3D excels in precise fovea localization even with high ***-2D shows high detection rates but lower accuracy especially in the high myopia *** both models offers a robust SFCT assessment approach,promising efficiency and accuracy for large-scale studies and clinical use.

关键词： subfoveal choroidal thickness optical coherence tomography automatic foveal detection automatic choroid segmentation

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