Operation mode selection of NIMBY facility Public Private Partnership projects

Construction of not in my back yard (NIMBY) facility Public Private Partnership (PPP) projects are feasible measures to realize sustainable urbanization. In order to ensure the smooth development of the NIMBY facility PPP projects, the problem of choosing the most suitable operation mode among many PPP modes is still scarce and unscientific. In order to select the operation mode of the PPP projects that best fits the characteristics of the project, this paper constructs the operation mode selection of the NIMBY facility PPP project. Firstly, the index system of operation mode selection of the NIMBY facility PPP project is determined. G1 subjective weighting method and information entropy objective weighting method are introduced to solve the optimal weight of each index. Grey correlation theory is used to improve TOPSIS method, and the calculation form of relative proximity degree is optimized to determine the most suitable operation mode for the project. In this paper, combined weighting and TOPSIS method are applied to the research of NIMBY facility PPP project, and the operation mode selection of NIMBY facility PPP project is established, which makes up the blank of this part. Finally, a PPP project in Qingdao, Shandong Province, China, is taken as an example to verify the applicability of the model. The effectiveness of this model was tested by comparing the results of TOPSIS method, Grey target model, Extended matter-element mode and GRA-TOPSIS. It is hoped to provide useful reference for the operation mode selection of NIMBY facility PPP project.

Measurement and Evaluation of Collaborative Development Level of Higher Education

With the aid of grey correlation theory and technique for order of preference by similarity to ideal solution (TOPSIS), this paper sets up a multi-dimensional evaluation index system (EIS) for the comprehensive development level (CDL) of China’s higher education, and quantifies the state of collaborative development in 2005-2017 with an improved distance collaboration model. The results show that: Being the premises and bases of higher education, the supply subsystem develops much slower than the other subsystems (i.e. participation, output, and environment), and clearly pulls the development of the other subsystems. From 2012 onwards, the subsystems conformed to basically the same trend for the degree of collaboration: the degree of collaboration tended to be stable. There was even a slight dent in overall degree of collaboration between 2012 and 2016. Hence, the overall degree of collaborative development was far slower than the overall degree of development. After more than a decade of development, the degree of development, degree of collaboration, and degree of collaborative development reached basically the same level in 2017. The empirical results shed new lights on the focal points of higher education development in China.

Study on microstructure influence mechanism to mechanical behavior of OGFC asphalt mixture

Microstructure characteristics of OGFC (open graded friction course) asphalt mixture are closely related to the mechanical behavior. To study the microstructure influence mechanism to mechanical behavior of OGFC asphalt mixture, the digital image processing technology is used to process the specimen’s fault images and obtain the microstructure parameters of the OGFC asphalt mixture with different gradation. At the same time, the microstructure influence on mechanical behavior of OGFC asphalt mixture is explored by using the Grey correlation theory based on the experimental results of mechanical performance and the microstructure parameters. The influence of four key sieve passing percentage (1.18, 2.36, 4.75, and 9.5 mm) on the microstructure was discussed by using the Grey correlation theory, and the influence mechanism to mechanical behavior of OGFC asphalt mixture was further revealed. The results show that with the increase of air void content, the total void area, the equivalent pore diameter, and the number of big voids (here, “big” means voids with an area greater than 10 mm2) increase, the length of void and corresponding void area increase synchronously, the drainage performance is enhanced, and the mechanical performance is decreased. With the increase of nominal maximum particle size, the average area of single void, the percentage of number of big voids, and the equivalent diameter increase, and the drainage performance, anti-skidding performance, and mechanical performance of pavement are enhanced. It is considered that the key sieve passing percentage affects the mechanical behavior by influencing the microstructure of asphalt mixtures. The influence degree of microstructure parameters on mechanical behavior and the influence degree of the key sieve passing percentage on microstructure parameters were obtained. The research results have a certain reference value for the optimization of mechanical behavior of OGFC asphalt mixture.