Statistical Assessment of Simplified CPTU-Based Hydraulic Conductivity Curves

Classical theoretical approaches to evaluate CPTU-based hydraulic conductivity gave the expression of a bilinear relation defined by K D - B q Q t , for undrained and drained soils. In fact, a dividing line may be selected with a certain degree of subjectivity, and several undrained/drained points occur in opposite sites, which may make us doubt the necessity of two intersecting lines to distinguish the undrained and drained soils. And a uniform and relatively simple curve including an arc, parabola, or ellipse correlation may be more suitable and accessible from a practical point of view. A database in the Yangtze Delta region has been collated to assess the three curves compared with the bilinear line. With the graphical and statistical analyses, the results indicate that the arc, parabola, and ellipse simplified curves could give better performance than the bilinear line. Through the statistical analyses and the number of variables, the overall best curve was the ellipse with only two variables, which is expected to improve the application scope and simplicity of hydraulic conductivity.

Total Factor Energy Productivity and Efficiency in the Yangtze Delta Region: An Application of DEA-Malmquist Index

This paper used data envelopment analysis (DEA)-Malmquist index method to analyze the total factors energy productivity (TFEP) and efficiency of 16 cities in the Yangtze Delta region from the year 2008 to 2012. According to the computational results, the average TFEP of 16 cities during 1998-2012 is 0.978, and the average total factor energy efficiency (TFEE) is 1.011, while the average total factor energy technological change (TFTC) is 0.969. So the rapid drop of TFEP is mainly ascribable to the rapid drop of TFTC in the Yangtze Delta region. Specific to different cities and different period, there exists significant inequality catch-up effect and innovation effect in the Yangtze Delta region. In which, the catch-up effect of Nanjing, Suzhou, Yangzhou, Changzhou, Zhenjiang, Nantong, Taizhou1 and Jiaxing is evident, while the innovation effect of Shanghai, Nanjing, Suzhou, Wuxi and Zhoushan is more significant.

Study on the Effect of Foreign Direct Investment and Foreign Trade on Energy Efficiency in the Yangtze Delta Region Using Stochastic Frontier Analysis Approach

With the development of an open economy in the Yangtze Delta region, energy has increasingly become an bottleneck for rapid economic development. Opening up will promote economic expansion and affect the efficiency of energy utilization in the process of economic development. The proper evaluation of the impact of opening up on the efficiency of energy utilization will help the intensity and direction of open door policy adjustment. The paper used the stochastic frontier analysis (SFA) approach to investigate the effect of foreign direct investment (FDI) and foreign trade on the efficiency of energy utilization of the Yangtze Delta region in China. The results show that FDI and foreign trade both are very vital for the improvement of the efficiency of energy utilization. Moreover, the elastic of FDI on the energy efficiency is larger than the elastic of foreign trade on the energy efficiency.