期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
数字金融能改善企业投资效率吗——基于代理摩擦机制和管理者学习机制的分析 被引量:2
1
作者 黄实磊 吴翌琳 《调研世界》 CSSCI 2024年第4期76-88,共13页
本文利用2011—2020年我国上市公司数据,基于代理摩擦机制和管理者学习机制双重视角,考察数字金融对企业投资效率的影响。研究发现,数字金融显著降低了企业非效率投资,工具变量回归、双重差分策略、改变核心变量等稳健性检验表明结果稳... 本文利用2011—2020年我国上市公司数据,基于代理摩擦机制和管理者学习机制双重视角,考察数字金融对企业投资效率的影响。研究发现,数字金融显著降低了企业非效率投资,工具变量回归、双重差分策略、改变核心变量等稳健性检验表明结果稳健。异质性分析表明,数字金融降低非效率投资的作用对分析师预测离散度高、外部监督弱、资本市场信息效率低、经营不确定性高的企业更明显,验证了数字金融降低代理摩擦和增进管理者学习的作用。渠道分析发现,数字金融改善了会计信息质量,降低了股东—经理人代理成本,提升了企业投资—投资机会敏感度。进一步研究发现,数字金融降低非效率的作用对非国有企业更显著;数字金融对过度投资和投资不足都有显著抑制作用,对融资约束低的企业更显著地抑制过度投资,对融资约束高的企业更显著地降低投资不足。 展开更多
关键词 数字金融 投资效率 代理摩擦 管理者学习
下载PDF
One neural network approach for the surrogate turbulence model in transonic flows 被引量:2
2
作者 Linyang Zhu Xuxiang Sun +1 位作者 Yilang Liu Weiwei Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2022年第3期38-51,I0002,共15页
With the rapid development of artificial intelligence techniques such as neural networks,data-driven machine learning methods are popular in improving and constructing turbulence models.For high Reynolds number turbul... With the rapid development of artificial intelligence techniques such as neural networks,data-driven machine learning methods are popular in improving and constructing turbulence models.For high Reynolds number turbulence in aerodynamics,our previous work built a data-driven model applicable to subsonic airfoil flows with different free stream conditions.The results calculated by the proposed model are encouraging.In this work,we aim to model the turbulence of transonic wing flows with fully connected deep neural networks,where there is less research at present.The proposed model is driven by two flow cases of the ONERA(Office National d'Etudes et de Recherches Aerospatiales)wing and coupled with the Navier-Stokes equation solver.Four subcritical and transonic benchmark cases of different wings are used to evaluate the model performance.The iteration process is stable,and final convergence is achieved.The proposed model can be used to surrogate the traditional Reynolds averaged Navier-Stokes turbulence model.Compared with the data calculated by the Spallart-Allmaras model,the results show that the proposed model can be well generalized to the test cases.The mean relative error of the drag coefficient at different sections is below 4%for each case.This work demonstrates that modeling turbulence by data-driven methods is feasible and that our modeling pattern is effective. 展开更多
关键词 Deep neural network Turbulence modeling TRANSONIC High Reynolds number
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部