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数字化转型、供应链透明度与供应链绩效——来自中国A股制造业上市公司的经验证据

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南京财经大学学报 2024年第4期 89-99页

作者：井辉范雨薇郑州大学商学院河南郑州450001

在复杂多变的环境下,数字技术的发展为企业供应链绩效的改进提供了条件。基于资源基础理论、信息不对称理论和组织信息处理理论,分析数字化转型对供应链绩效的影响机制,并运用2015—2021年中国A股制造业上市公司的样本数据,对提出的假... 详细信息

在复杂多变的环境下,数字技术的发展为企业供应链绩效的改进提供了条件。基于资源基础理论、信息不对称理论和组织信息处理理论,分析数字化转型对供应链绩效的影响机制,并运用2015—2021年中国A股制造业上市公司的样本数据,对提出的假设进行检验。结果发现:数字化转型对供应链绩效有显著的正向影响,供应链透明度在数字化转型与供应链绩效的关系中起着部分中介效应,环境不确定性正向调节数字化转型与供应链绩效的关系、数字化转型与供应链透明度的关系,结论在经过一系列稳健性测试后依然成立。异质性分析结果显示,数字化转型与供应链绩效的关系会受企业规模的影响,具体表现为数字化转型对供应链绩效的影响在中小型制造企业中更明显。研究结论为中国的制造企业尤其是中小型制造企业推进数字化转型、提升供应链透明度和提高供应链绩效提供了理论依据。

关键词：数字化转型供应链透明度环境不确定性供应链绩效

Solving Traveltime Tomography with Deep Learning

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Communications in Mathematics and Statistics 2023年第1期11卷 3-19页

作者： yuwei fan Lexing Ying Department of Mathematics Stanford UniversityStanfordCA 94305USA

This paper introduces a neural network approach for solving two-dimensional traveltime tomography(TT)problems based on the eikonal *** mathematical problem of TT is to recover the slowness field of a medium based on the boundary measurement of the traveltimes of waves going through the *** inverse map is high-dimensional and *** the circular tomography geometry,a perturbative analysis shows that the forward map can be approximated by a vectorized convolution operator in the angular *** by this and filtered backprojection,we propose an effective neural network architecture for the inverse map using the recently proposed BCR-Net,with weights learned from training *** results demonstrate the efficiency of the proposed neural networks.

关键词： Traveltime tomography Eikonal equation Inverse problem Neural networks Convolutional neural network

Superfluid density of two-dimensional weakly interacting boson system at zero temperature

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Chinese Science Bulletin 2011年第12期56卷 1230-1233页

作者： HE PeiSong fan yuwei School of Physics Peking University Beijing 100871 China Yuanpei College Peking University Beijing 100871 China

We compute the superfluid density of a two-dimensional boson system with weak two-body repulsive interactions at zero temperature using one-loop perturbation theory in the weak coupling region. The boson fields are taken to be in continuum form in real space, and the interactions are approximated by a δ function of the distance between the bosons. We find that the one-loop fluctuations slightly decrease the superfluid density of a classical level. The superfluid density is approximated by the condensate density multiplied by the mass of the boson particle.

关键词：玻色子系统弱相互作用流密度温度二维摄动理论现实空间函数近似

Dimension-Reduced Hyperbolic Moment Method for the Boltzmann Equation with BGK-Type Collision

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Communications in Computational Physics 2014年第5期15卷 1368-1406页

作者： Zhenning Cai yuwei fan Ruo Li Zhonghua Qiao School of Mathematical Sciences Peking UniversityBeijing 100871China CAPT LMAM&School of Mathematical SciencesPeking UniversityBeijing 100871China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHung HomHong Kong.

We develop the dimension-reduced hyperbolic moment method for the Boltzmann equation,to improve solution efficiency using a numerical regularized moment method for problems with low-dimensional macroscopic variables and highdimensional microscopic *** the present work,we deduce the globally hyperbolic moment equations for the dimension-reduced Boltzmann equation based on the Hermite expansion and a globally hyperbolic *** numbers of Maxwell boundary condition required for well-posedness are *** numerical scheme is then developed and an improved projection algorithm between two different Hermite expansion spaces is *** solving several benchmark problems,we validate the method developed and demonstrate the significant efficiency improvement by dimension-reduction.

关键词： Dimension-reduction moment system NRxx global hyperbolicity boundary condition microflow

膝关节单髁置换与全膝关节置换治疗膝关节单间室骨性关节炎疗效比较

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宁夏医科大学学报 2024年第8期46卷 797-800页

作者：范玉伟赵治龙陈科何亚洲武群固原市人民医院骨科固原756000

目的对比膝关节单髁置换与全膝关节置换治疗膝关节单间室骨性关节炎疗效。方法选择2020年3月至2023年3月固原市人民医院骨科收治的120例膝关节单间室骨性关节炎患者为研究对象,根据治疗方案的不同分为两组,其中60例患者接受膝关节单... 详细信息

目的对比膝关节单髁置换与全膝关节置换治疗膝关节单间室骨性关节炎疗效。方法选择2020年3月至2023年3月固原市人民医院骨科收治的120例膝关节单间室骨性关节炎患者为研究对象,根据治疗方案的不同分为两组,其中60例患者接受膝关节单髁置换术治疗(A组),另外60例患者接受全膝关节置换术治疗(B组)。对比两组手术时间、住院时间、血红蛋白(Hb)水平、血细胞比容(Hct)水平、疼痛视觉模拟量表(VAS)评分、膝关节功能评分系统(HSS)评分、Berg平衡量表评分、起立一行走计时测试(TUG)结果、膝关节活动度。结果 A组手术时间及住院时间均短于B组(P均<0.05)。术后1、3 d,A组Hb、Hct水平均高于B组(P均<0.05),且两组术后3 d均低于术后1 d(P均<0.05);术后1、3 d,A组VAS评分低于B组,且两组术后3 d均低于术后1 d(P均<0.05)。术后1、3个月,A组HSS评分、Berg平衡量表评分、膝关节活动度均高于B组(P均<0.05),但术后3个月高于术后1个月(P<0.05);术后1、3个月,A组TUG测试结果均低于B组(P均<0.05),且术后3个月低于术后1个月(P<0.05)。结论相比于全膝关节置换术,膝关节单髁置换术可缩短患者手术时间和住院时间,更有助于患者膝关节功能的恢复。

关键词：膝关节单髁置换全膝关节置换膝关节单间室骨性关节炎疗效

Machine Learning Analysis of Impact of Western US Fires on Central US Hailstorms

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Advances in Atmospheric Sciences 2024年第7期41卷 1450-1462页

作者： Xinming LIN Jiwen fan yuwei ZHANG ZJason HOU Pacific Northwest National Laboratory RichlandWA 99354USA Argonne National Laboratory LemontIL 60439USA

Fires,including wildfires,harm air quality and essential public services like transportation,communication,and *** fires can also influence atmospheric conditions,including temperature and aerosols,potentially affecting severe convective ***,we investigate the remote impacts of fires in the western United States(WUS)on the occurrence of large hail(size:≥2.54 cm)in the central US(CUS)over the 20-year period of 2001–20 using the machine learning(ML),Random Forest(RF),and Extreme Gradient Boosting(XGB)*** developed RF and XGB models demonstrate high accuracy(>90%)and F1 scores of up to 0.78 in predicting large hail occurrences when WUS fires and CUS hailstorms coincide,particularly in four states(Wyoming,South Dakota,Nebraska,and Kansas).The key contributing variables identified from both ML models include the meteorological variables in the fire region(temperature and moisture),the westerly wind over the plume transport path,and the fire features(i.e.,the maximum fire power and burned area).The results confirm a linkage between WUS fires and severe weather in the CUS,corroborating the findings of our previous modeling study conducted on case simulations with a detailed physics model.

关键词： wildfire severe convective storm hailstorm machine learning

Estimating blue marlin(Makaira nigricans)sustainable yield in the Indian Ocean using a data-poor approach

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Aquaculture and Fisheries 2019年第3期4卷 122-127页

作者： yuwei fan Zhe Geng Jiangfeng Zhu Xiaojie Dai Kindong Richard College of Marine Sciences Shanghai Ocean UniversityShanghai201306China Key Laboratory of Oceanic Fisheries Exploration Shanghai Ocean UniversityMinistry of AgricultureShanghai201306China National Engineering Research Center for Oceanic Fisheries Shanghai201306China Scientific Observing and Experimental Station of Oceanic Fisheries Resources and Environment Ministry of AgricultureShanghai201306China

Blue marlin(Makaira nigricans)is a common bycatch species in the global tuna longline *** this study,we applied a common data-poor approach,i.e.,depletion-corrected average catch(DCAC)to assess stock status of the Indian Ocean blue *** yield(Ysust),one reference point in this case,was estimated,and its uncertainty was integrated by using Monte Carlo *** results revealed the estimate of Ysust by DCAC was lower than MSY of 11,926 t by BSP-SS and is also lower than the provisional reference point of 11,704 t by the management *** is reliable for blue marlin in driving precautionary management quantity based on the CPUE of Japan(1980–2015).This study also implies that DCAC could be applied to other billfish stocks and uncertainty be estimated for sustainable ***,data-poor methods could be adjusted with precautionary approaches.

关键词： Blue marlin Data-poor approach Stock assessment Indian Ocean

超早产儿生后不同日龄发生中/重度支气管肺发育不良的预测模型构建

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新医学 2024年第7期55卷 549-556页

作者：古健樊雨薇龙欢夏昌顺范斯潆李苑钟怡钟鑫琪广州医科大学附属第三医院新生儿科广东省产科重大疾病重点实验室广东省妇产疾病临床医学研究中心粤港澳母胎医学高校联合实验室广东广州510150

目的构建超早产儿生后不同日龄发生中/重度支气管肺发育不良(BPD)的预测模型。方法回顾性选取2017年9月至2019年12月期间在广州医科大学附属第三医院出生、胎龄<28周且诊断为BPD的超早产儿为研究对象,分为轻度BPD和中/重度BPD 2组,将单... 详细信息

目的构建超早产儿生后不同日龄发生中/重度支气管肺发育不良(BPD)的预测模型。方法回顾性选取2017年9月至2019年12月期间在广州医科大学附属第三医院出生、胎龄<28周且诊断为BPD的超早产儿为研究对象,分为轻度BPD和中/重度BPD 2组,将单因素分析中P<0.05变量纳入多因素Logistic回归进行风险评估分析,建立早期预测模型,进行验证并评估预测效能。结果共纳入研究对象90例,其中轻度BPD组和中/重度BPD组分别为58例(64.4%)和32例(35.6%)。多因素Logistic回归分析结果显示,超早产儿生后7日龄影响中/重度BPD发生的因素有出生体质量、孕母孕前BMI≥25 kg/m^(2)、出生后1分钟Apgar评分≤7分和肺炎。14日龄危险因素有子痫前期、孕母孕前BMI≥25 kg/m^(2)、肺炎和具有血流动力学意义动脉导管未闭(hsPDA)。28日龄危险因素有子痫前期、孕母孕前BMI≥25 kg/m^(2)、有创机械通气时间和hsPDA。生后7、14和28日龄预测模型的ROC曲线下AUC值分别为0.864(95%CI 0.776~0.952)、0.860(95%CI 0.774~0.946)和0.863(95%CI 0.783~0.944)。基于高危因素构建列线图模型,校准后曲线接近参考线,预测值与实际值接近,模型具有较好的校准度。结论超早产儿生后第7、14、28日龄时发生中/重度BPD的危险因素略有差别,主要集中在出生体质量、孕母孕前BMI≥25 kg/m^(2)、生后1分钟Apgar评分≤7分、肺炎、子痫前期、hsPDA和有创机械通气天数等指标,根据不同因素所构建的不同时间点的预测模型均具有较好的预测价值,可以为临床提供指导。

关键词：超早产儿支气管肺发育不良危险因素预测模型

Compact intense electron-beam accelerators based on high energy density liquid pulse forming lines

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Matter and Radiation at Extremes 2018年第6期3卷 278-292页

作者： Jianhua Yang Zicheng Zhang Hanwu Yang Jun Zhang Jinliang Liu Yi Yin Tao Xun Xinbing Cheng yuwei fan Zhenxing Jin Jinchuan Ju College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073People's Republic of China State Key Laboratory of Pulsed Power Laser Technology National University of Defense TechnologyChangsha 410073People's Republic of China

This paper provides a review of the compact intense electron-beam accelerators (IEBAs) based on liquid pulse forming lines (PFLs) that havebeen developed at the National University of Defense Technology (NUDT) in China. The history and roadmap of the compact IEBAs used todrive high-power microwave (HPM) devices at NUDT are reviewed. The properties of both de-ionized water and glycerin as energy storagemedia are presented. Research into the breakdown properties of liquid dielectrics and the desire to maximize energy storage have resulted in theinvention of several coaxial PFLs with different electromagnetic structures, which are detailed in this paper. These high energy density liquidPFLs have been used to increase the performance of IEBA subsystems, based on which the SPARK (Single Pulse Accelerator with spark gaps)and HEART (High Energy-density Accelerator with Repetitive Transformer) series of IEBAs were constructed. This paper also discusses howthese compact IEBAs have been used to drive typical HPM devices and concludes by summarizing the associated achievements and theconclusions that can be drawn from the results.

关键词： High-power microwave(HPM) Intense electron-beam accelerator(IEBA) Pulsed power technology(PPT) Pulse forming line(PFL) Fluid of high energy density De-ionized water Glycerin