As Busan New Port has been developed with a total scale of 30 berths in 2020, the chronic problem of Busan port, a lack of port facilities, is being addressed, and there is a growing interest in regard to port develop...As Busan New Port has been developed with a total scale of 30 berths in 2020, the chronic problem of Busan port, a lack of port facilities, is being addressed, and there is a growing interest in regard to port development with an optimal scale. The Korean container port development under the master plan for national port development reveals a severe problem of excess supply of port facility in some ports. This paper, the authors analysed the second and the third master plan for national port development implemented in 2001 and 2011, and a revised plan in 2006, along with the amended predictions for container throughput. Furthermore, the effectiveness of the implementation of the initial plan, and the current situation of South Korea＇s main container ports of Busan, Gwangyang, Incheon, and Pyeongtaek ＆ Dangjin was examined. Through the analysis of port vitalizations, we have examined the actual problems for the prediction of container throughput. Also, this research analysed the functional difference of each port and organized the function of each one discriminatively. Therefore, identifies the problems, which arise with making the container throughput forecasts, which is a fimdamental aspect of existing port development policy, and suggest a direction for future port development by synthesizing the results of analysis.展开更多
Electro-hydraulic proportional valve is the core control valve in many hydraulic systems used in agricultural and engineering machinery.To address the problem related to the large throttling losses and poor stability ...Electro-hydraulic proportional valve is the core control valve in many hydraulic systems used in agricultural and engineering machinery.To address the problem related to the large throttling losses and poor stability typically associated with these valves,here,the beneficial effects of a triangular groove structure on the related hydraulic response are studied.A mathematical model of the pressure compensation system based on the power-bond graph method is introduced,and the AMESim software is used to simulate its response.The results show that the triangular groove structure increases the jet angle and effectively compensates for the hydrodynamic force.The steady-state differential pressure at the valve port of the new pressure compensation structure was 0.65 MPa.Furthermore,experimental results show that the pressure difference at the main valve port is 0.73 MPa,and that the response time is less than 0.2 s.It is concluded that the new compensation structure has good pressure compensation response characteristics.展开更多
文摘As Busan New Port has been developed with a total scale of 30 berths in 2020, the chronic problem of Busan port, a lack of port facilities, is being addressed, and there is a growing interest in regard to port development with an optimal scale. The Korean container port development under the master plan for national port development reveals a severe problem of excess supply of port facility in some ports. This paper, the authors analysed the second and the third master plan for national port development implemented in 2001 and 2011, and a revised plan in 2006, along with the amended predictions for container throughput. Furthermore, the effectiveness of the implementation of the initial plan, and the current situation of South Korea＇s main container ports of Busan, Gwangyang, Incheon, and Pyeongtaek ＆ Dangjin was examined. Through the analysis of port vitalizations, we have examined the actual problems for the prediction of container throughput. Also, this research analysed the functional difference of each port and organized the function of each one discriminatively. Therefore, identifies the problems, which arise with making the container throughput forecasts, which is a fimdamental aspect of existing port development policy, and suggest a direction for future port development by synthesizing the results of analysis.
基金This research was funded by the 2020 Shandong Province Key Research and Development Programs(Major Technological Innovation Projects):Construction Machinery Integration Research and Application of Key Technologies for Intelligent Integration and Matching of Vehicle Assembly(2020CXGC011005)Large Tractor Hydraulic CVT Intelligent Continuously Variable Transmission Integration Research and Application(2020CXGC010806)Development and Application of High-Horsepower High-Efficiency Intelligent Tractors(2021CXGC010812).
文摘Electro-hydraulic proportional valve is the core control valve in many hydraulic systems used in agricultural and engineering machinery.To address the problem related to the large throttling losses and poor stability typically associated with these valves,here,the beneficial effects of a triangular groove structure on the related hydraulic response are studied.A mathematical model of the pressure compensation system based on the power-bond graph method is introduced,and the AMESim software is used to simulate its response.The results show that the triangular groove structure increases the jet angle and effectively compensates for the hydrodynamic force.The steady-state differential pressure at the valve port of the new pressure compensation structure was 0.65 MPa.Furthermore,experimental results show that the pressure difference at the main valve port is 0.73 MPa,and that the response time is less than 0.2 s.It is concluded that the new compensation structure has good pressure compensation response characteristics.
