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Kunming, China

The Yunnan University of Finance and Economics is a provincial-level university in Kunming, Yunnan province, China focusing on fields related to commerce and management. Wikipedia.

Zhou W.,Yunnan University of Finance and Economics
Journal of Intelligent and Fuzzy Systems

A crucial issue related to the Atanassov's intuitionistic fuzzy operators is how to determine their weights. Various weighted methods have been proposed last decades, but it seems that there is no investigation on the monotonous and proportion-invariant properties, which is decisive for aggregation and comparison of Atanassov's intuitionistic fuzzy values in group decision making. In this paper, we propose a novel weighted method, i.e., precisely weighted method, to calculate Atanassov's intuitionistic fuzzy aggregation operator weights, and prove its monotonicity and proportion-invariance. Then, we develop two weighted aggregation operators based on this new method, i.e. the Atanassov's intuitionistic fuzzy ordered precisely weighted averaging (A-IFOPWA) operator and the Atanassov's intuitionistic fuzzy ordered precisely weighted geometric (A-IFOPWG) operator. Furthermore, some of their desirable properties are investigated in detail. Finally, a practical example is provided to illustrate the precisely weighted method and the developed aggregation operators. © 2014 - IOS Press. Source

Zhou W.,Yunnan University of Finance and Economics
International Journal of Intelligent Systems

As a generalization of fuzzy sets, hesitant fuzzy set is a very useful technique to represent decision makers' hesitancy in decision making. Various hesitant fuzzy weighted operators have been developed to aggregate hesitant fuzzy information, but it seems that there is no investigation on the weighted approach of obtaining their weights, which is decisive for the calculation and comparison of hesitant fuzzy elements (HFEs) in multicriteria group decision making. In this paper, we propose an accurate weighted method (AWM) of monotonicity and proportionality, based on nothing but the score function and the new deviation function. Because of the above properties, AWM may be an accurate and objective technique to calculate the weights of HFEs and aggregation operator. Then, based on this weighted approach, we develop two new hesitant fuzzy ordered weighted aggregation operators, that is, hesitant fuzzy ordered accurate weighted averaging and hesitant fuzzy ordered accurate weighted geometric operators, and study their relationships and properties. In the end, an illustrative project investment problem is used to demonstrate how to apply the proposed weighted approach and to observe the computational consequences resulting from new aggregation operators. This work contributes significantly to improve the hesitant fuzzy theory, and proposes two new hesitant fuzzy aggregation operators. © 2014 Wiley Periodicals, Inc. Source

Wang J.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Mo H.,China Communications and Transportation Association | Wang F.,Yunnan University of Finance and Economics
Journal of Transport Geography

This paper analyzes the evolution process of the air transport network of China (ATNC) since 1930. Based on the network analysis results, the ATNC has significantly improved in connectivity based on (1) rising alpha, beta and gamma indices, (2) declining diameter and centre index and (3) decreasing average path length and increasing clustering coefficient. The network centralization index reveals a fluctuation phase before 1952, a pre-1980 centralization phase before the economic reform era, a centralization phase after the mid-1990s deregulation, and a decentralization phase between. The k-core decomposition method helps identify the evolution of core network and hierarchy of the ATNC over time. The spatial development model characterizes its structure change in six stages: (1) scattered development, (2) trunk line connection, (3) circular linkage, (4) hub formation, (5) a complex network structure, and (6) emerging multi-airport systems. © 2014 Elsevier Ltd. All rights reserved. Source

Wang H.,Yunnan University of Finance and Economics | Wang H.,National University of Singapore
Journal of Computational Physics

In this paper, we extend the efficient time-splitting Fourier pseudospectral method to solve the generalized Gross-Pitaevskii (GP) equations, which model the dynamics of spin F= 2 Bose-Einstein condensates at extremely low temperature. Using the time-splitting technique, we split the generalized GP equations into one linear part and two nonlinear parts: the linear part is solved with the Fourier pseudospectral method; one of nonlinear parts is solved analytically while the other one is reformulated into a matrix formulation and solved by diagonalization. We show that the method keeps well the conservation laws related to generalized GP equations in 1D and 2D. We also show that the method is of second-order in time and spectrally accurate in space through a one-dimensional numerical test. We apply the method to investigate the dynamics of spin F= 2 Bose-Einstein condensates confined in a uniform/nonuniform magnetic field. © 2011 Elsevier Inc. Source

Dai D.,Georgia State University | Wang F.,Yunnan University of Finance and Economics
Environment and Planning B: Planning and Design

Disparities in accessibility to healthy food are a critical public-health concern. Poor access to reasonably priced, nutritious, and good-quality food may lead to poor diet and increase the risks of health problems such as obesity, diabetes, and cardiovascular diseases. This research advances the popular two-step floating catchment area (2SFCA) method by incorporating a kernel density (KD) function to form the 'KD2SFCA method'. The study applies the method to measure the spatial access to food stores in southwest Mississippi, and examines the interaction between the spatial access and nonspatial factors. The research shows that neighborhoods with higher scores of urban socioeconomic disadvantage actually have better spatial accessibility to food stores; but higher percentages of carless households and lower income in some neighborhoods may compromise overall accessibility. Neighbor-hoods with stronger cultural barriers tend to be associated with poorer spatial accessibility. The study clearly differentiates spatial and nonspatial factors in access inequalities, and thus helps policy makers to design corresponding remedial strategies. © 2011 Pion Ltd and its Licensors. Source

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