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Properties of Phase Transition of Traffic Flow on Urban Expressway Systems with Ramps and Accessory Roads

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Communications in Theoretical Physics 2011年第11期56卷 945-951页

作者：梅超群刘业进 school of Statistics Capital University of Economics and Business school of Urban economics and Public Affair Capital University of Economics and Business

In this paper, we develop a cellular automaton model to describe the phase transition of traffic flow on urban expressway systems with on-off-ramps and accessory roads. The lane changing rules are given in detailed, the numerical results show that the main road and the accessory road both produce phase transitions. These phase transitions will omen be influenced by the number of lanes, lane changing, the ramp flow, the input flow rate, and the geometry structure.

关键词： traffic flow ramp phase transition

Hierarchical hesitant fuzzy K-means clustering algorithm

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Applied Mathematics(A Journal of Chinese Universities) 2014年第1期29卷 1-17页

作者： CHEN Na XU Ze-shui XIA Mei-mei school of economics and Management Southeast University school of Applied Mathematics Nanjing University of Finance and Economics Business school Sichuan University school of economics and Management Tsinghua University

Due to the limitation and hesitation in one＇s knowledge, the membership degree of an element to a given set usually has a few different values, in which the conventional fuzzy sets are invalid. Hesitant fuzzy sets are a powerful tool to treat this case. The present paper focuses on investigating the clustering technique for hesitant fuzzy sets based on the K-means clustering algorithm which takes the results of hierarchical clustering as the initial clusters. Finally, two examples demonstrate the validity of our algorithm.

关键词： 90B50 68T10 62H30 Hesitant fuzzy set hierarchical clustering K-means clustering intuitionisitc fuzzy set

Cross-country income disparity and its effect on carbon emissions

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Chinese Journal of Population,Resources and Environment 2013年第1期11卷 33-50页

作者： Lin Guo graduate school of economics Nagoya UniversityNagoya 464-8601Japan

This study is motivated by the interesting relationship between the income Kuznets curve and the carbon Kuznets *** paper focuses on the interaction effects of income distribution and income per capita on CO_2 emissions using country group panel data over the period of 1980 to 2006 by employing fixed effects(FE),random effects(RE)and feasible generalized least squares(FGLS)estimation *** main findings are as follows.(1)There exists an inverted-U relationship between CO_2 emissions per capita and income per capita in all sample countries and high-income groups.(2)The cross-country income disparity has a negative effect on the average level of CO_2 emissions but a positive effect on the aggregate income elasticity of CO_2 emissions.(3)This negative effect of income disparity on the average level of CO_2emissions decreases along with the growth of per capita ***,economic growth contributes to the reduction of this negative impact.

关键词： CO_2 emissions income disparity carbon Kuznets curve income elasticity disparity elasticity

Two 8-node quadrilateral spline elements by B-net method

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Acta Mechanica Sinica 2012年第6期28卷 1620-1629页

作者： Juan Chen Chong-Jun Li school of Mathematics and Quantitative economics Dongbei University of Finance and Economics school of Mathematical Sciences Dalian University of Technology

Isoparametric quadrilateral elements are widely used in the finite element method, but the accuracy of the isoparametric quadrilateral elements will drop obviously deteriorate due to mesh distortions. Spline functions have some properties of simplicity and conformality. Two 8-node quadrilateral elements have been developed using the trian- gular area coordinates and the B-net method, which can ex- actly model the quadratic field for both convex and concave quadrangles. Some appropriate examples are employed to evaluate the performance of the proposed elements. The nu- merical results show that the two spline elements can obtain solutions which are highly accurate and insensitive to mesh distortions.

关键词： Spline finite element B-net method Quadri-lateral element - Bivariate spline interpolation The secondorder completeness

Development of quadrilateral spline thin plate elements using the B-net method

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Acta Mechanica Sinica 2013年第4期29卷 567-574页

作者： Juan Chen Chong-Jun Li school of Mathematics and Quantitative economics Dongbei University of Finance and Economics school of Mathematical Sciences Dalian University of Technology

The quadrilateral discrete Kirchhoff thin plate bending element DKQ is based on the isoparametric element Q8, however, the accuracy of the isoparametric quadrilateral elements will drop significantly due to mesh distortions. In a previous work, we constructed an 8-node quadrilateral spline element L8 using the triangular area coordinates and the B- net method, which can be insensitive to mesh distortions and possess the second order completeness in the Cartesian co- ordinates. In this paper, a thin plate spline element is devel- oped based on the spline element L8 and the refined tech- nique. Numerical examples show that the present element indeed possesses higher accuracy than the DKQ element for distorted meshes.

关键词： Spline finite element ~ Refined quadrilateral el-ement ~ Discrete Kirchhoff plate element ~ Triangular areacoordinates ~ B-net method

Semiparametric estimation of average treatment effect through a random coefficient dummy endogenous variable model

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Science China Mathematics 2014年第11期57卷 2415-2428页

作者： ZHOU YaHong WANG LiMing HE XiaoDan school of economics Shanghai University of Finance and EconomicsKey Laboratory of Mathematical Economics (SUFE) school of Statistics and Management Shanghai University of Finance and Economics school of economics Shanghai University of Finance and Economics

This paper provides an estimation procedure for average treatment effect through a random coefficient dummy endogenous variable model. A leading example of the model is estimating the effect of a training program on earnings. The model is composed of two equations:an outcome equation and a decision *** the linear restriction in outcome and decision equations,Chen(1999) provided a distribution-free estimation procedure under conditional symmetric error distributions. In this paper we extend Chen's estimator by relaxing the linear index into a nonparametric function,which greatly reduces the risk of model misspecification. A two-step approach is proposed:the first step uses a nonparametric regression estimator for the decision variable,and the second step uses an instrumental variables approach to estimate average treatment effect in the outcome equation. The proposed estimator is shown to be consistent and asymptotically normally distributed. Furthermore,we investigate the finite performance of our estimator by a Monte Carlo study and also use our estimator to study the return of college education in different periods of China. The estimates seem more reasonable than those of other commonly used estimators.

关键词： random-coefficient model endogenous variable model symmetry

COOPERATIVE ADVERTISING AND PRICING MODELS IN A DYNAMIC MARKETING CHANNEL

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Journal of Systems Science and Systems Engineering 2014年第1期23卷 94-110页

作者： Mingyang ZHOU Jie LIN school of economics and Management Tongji University

This paper studies dynamic pricing and cooperative advertising strategies in a two-member channel of distribution. We propose differential game models that incorporate the carryover effects of advertising over time for both manufacturer and retailer. Two different models are studied. Firstly, we discussed a non-cooperative differential game which the manufacturer supports partially the cost of the promotion activities. Secondly, both channel members cooperatively determine their respective strategies. In these two cases, dynamic cooperative advertising and pricing strategies are characterized. Then numerical simulation method is applied to analyze the sensitivity of main model parameters and compare the main results of the two models. The simulation results show that the cooperative model achieves better coordination than the non-cooperative model with the following features： all channel members achieve higher advertising efforts and profit level in the cooperative case rather than in the non-cooperative case.

关键词： Supply chain differential games cooperative advertising pricing

Hybrid customer requirements rating method for customer-oriented product design using QFD

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Journal of Systems Engineering and Electronics 2015年第3期26卷 533-543页

作者： Fang Wang Hua Li Aijun Liu Xiao Zhang school of economics and Management Xidian University

Quality function deployment （QFD） is a well-known customer-oriented product design methodology. Rating the final importance of customer requirements （CRs） is really a very es- sential starting point in the implementation of QFD, since it largely affects the target setting value of design requirements. This pa- per aims to propose a novel method to deal with the relative importance ratings （RIRs） of CRs problem considering customers＇ diversified requirements and unknown information on customers＇ weights, which is an indispensable process for determining the final importance ratings of CRs. First, a new concept of customer＇s assessment structure is proposed according to the basic idea of grey relational analysis （GRA）, and then a constrained nonlinear optimization model is constructed to describe the assessment information aggregation factors of CRs considering customers＇ personalized and diversified requirements. Furthermore, an im- mune particle swarm optimization （IPSO） algorithm is designed to solve the model, and the weight vector of customers is obtained. Finally, a car door design example is introduced to illustrate the novel hybrid GRA-IPSO method＇s potential application in deter- mining the RIRs of CRs.

关键词： quality function deployment (QFD) customer requirement (CR) grey relational analysis (GRA) mass customization(MC) immune particle swarm optimization (IPSO).

Water quality assessment in Qu River based on fuzzy water pollution index method

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Journal of Environmental Sciences 2016年第12期28卷 87-92页

作者： Ranran Li Zhihong Zou Yan An school of economics and Management Beihang University

A fuzzy improved water pollution index was proposed based on fuzzy inference system and water pollution index. This method can not only give a comprehensive water quality rank, but also describe the water quality situation with a quantitative value, which is convenient for the water quality comparison between the same ranks. This proposed method is used to assess water quality of Qu River in Sichuan, China. Data used in the assessment were collected from four monitoring stations from 2006 to 2010. The assessment results show that Qu River water quality presents a downward trend and the overall water quality in 2010 is the worst. The spatial variation indicates that water quality of Nanbashequ section is the pessimal. For the sake of comparison, fuzzy comprehensive evaluation and grey relational method were also employed to assess water quality of Qu River. The comparisons of these three approaches＇ assessment results show that the proposed method is reliable.

关键词： Water quality assessmentFuzzy inferenceWater pollution indexFuzzy comprehensive evaluation