An efficient multiregion model is introduced to calculate the electromagnetic scattering from a perfectly electrical conducting （PEC） rough surface with or without a PEC target above it. In the multiregion model, th...An efficient multiregion model is introduced to calculate the electromagnetic scattering from a perfectly electrical conducting （PEC） rough surface with or without a PEC target above it. In the multiregion model, the rough surface is split into multiple regions depending on their position along the rough surface. Two intermediate regions are chosen as the dominant region. If a target is located above the rough surface, the target will also be included in the dominant region. The method of moments （MOM） is only adopted on the dominant region to ensure validity. Hence, the new model can greatly reduce the number of unknowns associated with full MOM analysis. The induced electric currents on the other regions are obtained by approximately considering the mutual coupling between different regions along the rough surface. Compared with the published hybrid method, this new model is not only suitable for EM scattering from a target above a rough surface but also applicable for just rough surfaces. Several numerical simulations are presented to show the validity and efficiency of the multiregion model.展开更多
Purpose:The study evaluates the relative roles of Domestic-Funded Enterprises(DFEs)and Foreign-Funded Enterprises(FFEs)across Chinese provinces.It further examines how industrial structures differ by ownership at both...Purpose:The study evaluates the relative roles of Domestic-Funded Enterprises(DFEs)and Foreign-Funded Enterprises(FFEs)across Chinese provinces.It further examines how industrial structures differ by ownership at both regional and national scales.Drawing on these findings,the analysis traces the geographic shift of FFEs and offers evidence-based guidance for shaping foreign investment policy.Design/methodology/approach:This study uses Inter-Country Input-Output(ICIO)and Inter-Region Input-Output(IRIO)tables to build two extended datasets:Ownership-Extended Inter-Country Input-Output(OE-ICIO)and Ownership-Extended Multi-Region Input-Output(OE-IRIO)tables.These are then combined to construct the Regionally-Ownership Dually-Extended Multi-Regional Input-Output(RODE-MRIO)table and Global Domestic and Foreign Enterprises Network(GDFEN)model to explore the industrial relocation trends of FFEs in China.Findings:The results indicate that:(1)From 2010 to 2019,FFEs in China showed an overall decline in influence,profitability,and network robustness.(2)Eastern and developed regions saw a clear retreat of FFEs,with a shift toward domestic control.Central regions and more developed regions played a transitional role.Moreover,western and less developed regions remained stable but still relied on low-end and resource-based activities.(3)FFEs’influence has been gradually shifting towards less-developed central and western provinces due to rising labor costs and stricter environmental regulations.Research limitations:First,only general policy recommendations are proposed,without exploring the design of specific policy instruments.Second,the significant impact of recent trade measures on the behavior of FFEs has not been considered.Third,further research is needed to deepen the analysis by comparing regional ownership dynamics in China with those in other major economies.Practical implications:This research provides valuable insights for policymakers aiming to enhance regional economic development and improve China’s position within Global Value Chains(GVCs).Originality/value:The originality of this paper lies in its development of a new model that combines geographic,sectoral,and ownership dimensions.This model allows for a clearer analysis of the roles of foreign and DFEs in China’s regional economy.It offers insights into industrial transfer trends within global value chains and provides a framework for analyzing and forecasting future shifts.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 60971067)the Specialized Research Fund for the Doctoral Program of Higher Education,China (Grant No. 20100203110016)the Fundamental Research Funds for the Central Universities,China (Grant No. K50510070001)
文摘An efficient multiregion model is introduced to calculate the electromagnetic scattering from a perfectly electrical conducting （PEC） rough surface with or without a PEC target above it. In the multiregion model, the rough surface is split into multiple regions depending on their position along the rough surface. Two intermediate regions are chosen as the dominant region. If a target is located above the rough surface, the target will also be included in the dominant region. The method of moments （MOM） is only adopted on the dominant region to ensure validity. Hence, the new model can greatly reduce the number of unknowns associated with full MOM analysis. The induced electric currents on the other regions are obtained by approximately considering the mutual coupling between different regions along the rough surface. Compared with the published hybrid method, this new model is not only suitable for EM scattering from a target above a rough surface but also applicable for just rough surfaces. Several numerical simulations are presented to show the validity and efficiency of the multiregion model.
基金supported by National Natural Science Foundation of China(72471007)Beijing Municipal Social Science Foundation Planning Project(23ZGB005)Humanities and Social Science Foundation of Ministry of Education of the People's Republic of China(Grant No.23YJAZH041).
文摘Purpose:The study evaluates the relative roles of Domestic-Funded Enterprises(DFEs)and Foreign-Funded Enterprises(FFEs)across Chinese provinces.It further examines how industrial structures differ by ownership at both regional and national scales.Drawing on these findings,the analysis traces the geographic shift of FFEs and offers evidence-based guidance for shaping foreign investment policy.Design/methodology/approach:This study uses Inter-Country Input-Output(ICIO)and Inter-Region Input-Output(IRIO)tables to build two extended datasets:Ownership-Extended Inter-Country Input-Output(OE-ICIO)and Ownership-Extended Multi-Region Input-Output(OE-IRIO)tables.These are then combined to construct the Regionally-Ownership Dually-Extended Multi-Regional Input-Output(RODE-MRIO)table and Global Domestic and Foreign Enterprises Network(GDFEN)model to explore the industrial relocation trends of FFEs in China.Findings:The results indicate that:(1)From 2010 to 2019,FFEs in China showed an overall decline in influence,profitability,and network robustness.(2)Eastern and developed regions saw a clear retreat of FFEs,with a shift toward domestic control.Central regions and more developed regions played a transitional role.Moreover,western and less developed regions remained stable but still relied on low-end and resource-based activities.(3)FFEs’influence has been gradually shifting towards less-developed central and western provinces due to rising labor costs and stricter environmental regulations.Research limitations:First,only general policy recommendations are proposed,without exploring the design of specific policy instruments.Second,the significant impact of recent trade measures on the behavior of FFEs has not been considered.Third,further research is needed to deepen the analysis by comparing regional ownership dynamics in China with those in other major economies.Practical implications:This research provides valuable insights for policymakers aiming to enhance regional economic development and improve China’s position within Global Value Chains(GVCs).Originality/value:The originality of this paper lies in its development of a new model that combines geographic,sectoral,and ownership dimensions.This model allows for a clearer analysis of the roles of foreign and DFEs in China’s regional economy.It offers insights into industrial transfer trends within global value chains and provides a framework for analyzing and forecasting future shifts.
