This study estimates the level of technical efficiency about grain production for 16 provinces over the period 1988—1999,through an econometric estimation of stochastic frontier production function.Our econometric re...This study estimates the level of technical efficiency about grain production for 16 provinces over the period 1988—1999,through an econometric estimation of stochastic frontier production function.Our econometric results confirm the great heterogeneity in the provinces’ efficiency of grain production and uncorrelation between the economic developing level and technical efficienc.展开更多
The shape and thickness of the dome were investigated with the aim of optimizing the type II CNG storage vessels by using a finite element analysis technique. The thickness of the liners and reinforcing materials was ...The shape and thickness of the dome were investigated with the aim of optimizing the type II CNG storage vessels by using a finite element analysis technique. The thickness of the liners and reinforcing materials was optimized based on the requirement of the cylinder and dome parts. In addition, the shape of the dome, which is most suitable for type lI CNG storage vessels, was proposed by a process of review and analysis of various existing shapes, and the minimum thickness was established in this sequence： metal liners, composite materials and dome parts. Therefore, the new proposed shape products give a mass reduction of 4.8 kg（5.1%）展开更多
文摘This study estimates the level of technical efficiency about grain production for 16 provinces over the period 1988—1999,through an econometric estimation of stochastic frontier production function.Our econometric results confirm the great heterogeneity in the provinces’ efficiency of grain production and uncorrelation between the economic developing level and technical efficienc.
基金Project(2010-0008-277) supported by NCRC (National Core Research Center) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technologysupported for two years by Pusan National University Research Grant
文摘The shape and thickness of the dome were investigated with the aim of optimizing the type II CNG storage vessels by using a finite element analysis technique. The thickness of the liners and reinforcing materials was optimized based on the requirement of the cylinder and dome parts. In addition, the shape of the dome, which is most suitable for type lI CNG storage vessels, was proposed by a process of review and analysis of various existing shapes, and the minimum thickness was established in this sequence： metal liners, composite materials and dome parts. Therefore, the new proposed shape products give a mass reduction of 4.8 kg（5.1%）
