Four assessment methods （two pollution indexes and two fuzzy mathematical models） were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality...Four assessment methods （two pollution indexes and two fuzzy mathematical models） were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality was assessed as class Ⅳ （moderately polluted） for each soil with single-factor index method, and was identified to be classes Ⅳ, Ⅲ （slightly polluted）, Ⅲ, and Ⅲ for soils A, B, C, and D, respectively, with the comprehensive index model. In comparison with the single-factor index method, the comprehensive index model concerned both dominant parameter and average contribution of all factors to the integrated environmental quality. Using the two fuzzy mathematical methods （single-factor deciding and weighted average models）, the environmental risks were determined to be classes Ⅳ, Ⅲ, Ⅱ （clean）, and Ⅱ for soils A, B, C, and D, respectively. However, divergence of the membership degree to each pollution class still occurred between the two methods. In fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental risk assessment.展开更多
The objective of this work was to determine the location of emergency material warehouses. For the site selection problem of emergency material warehouses, the triangular fuzzy numbers are respectively demand of the d...The objective of this work was to determine the location of emergency material warehouses. For the site selection problem of emergency material warehouses, the triangular fuzzy numbers are respectively demand of the demand node, the distance between the warehouse and demand node and the cost of the warehouse, a bi-objective programming model was established with minimum total cost of the system and minimum distance between the selected emergency material warehouses and the demand node. Using the theories of fuzzy numbers, the fuzzy programming model was transformed into a determinate bi-objective mixed integer programming model and a heuristic algorithm for this model was designed. Then, the algorithm was proven to be feasible and effective through a numerical example. Analysis results show that the location of emergency material warehouse depends heavily on the values of degree a and weight wl. Accurate information of a certain emergency activity should be collected before making the decision.展开更多
Based on the fuzzy characters of eco-environmental quality conception and classification standards, the incompatibility of evaluation indexes, the statistical fluctuation of index values, an information entropy fuzzy ...Based on the fuzzy characters of eco-environmental quality conception and classification standards, the incompatibility of evaluation indexes, the statistical fluctuation of index values, an information entropy fuzzy matter-element model for evaluating regional eco-environmental quality is proposed by way of comprehensively utilizing such theories as information theory, fuzzy sets and matter-element theory, etc. As a case, the model established here is used to evaluate the eco-environmental quality of Lake Chaohu basin. In the case, the eco-environmental quality standards and the evaluated schemes are indicated as matter-elements, together. Through constructing compound fuzzy matter-element, probability compound fuzzy matter-element and self-information compound fuzzy matter- element, the information entropy of each matter-element （including evaluated schemes and classification standards） is calculated in the end. According to these obtained information entropy values, the evaluated schemes can be not only arranged in quality state order but also classified by classification standards .Study result shows that information entropy fuzzy matter-element model is suitable for regional eco-environmental quality assessment.展开更多
基金the PhD Fund of the National Education Ministry of China (No20030284038)the Interna-tional Foundation for Science (NoW/4215)
文摘Four assessment methods （two pollution indexes and two fuzzy mathematical models） were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality was assessed as class Ⅳ （moderately polluted） for each soil with single-factor index method, and was identified to be classes Ⅳ, Ⅲ （slightly polluted）, Ⅲ, and Ⅲ for soils A, B, C, and D, respectively, with the comprehensive index model. In comparison with the single-factor index method, the comprehensive index model concerned both dominant parameter and average contribution of all factors to the integrated environmental quality. Using the two fuzzy mathematical methods （single-factor deciding and weighted average models）, the environmental risks were determined to be classes Ⅳ, Ⅲ, Ⅱ （clean）, and Ⅱ for soils A, B, C, and D, respectively. However, divergence of the membership degree to each pollution class still occurred between the two methods. In fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental risk assessment.
基金Project(71071162)supported by the National Natural Science Foundation of China
文摘The objective of this work was to determine the location of emergency material warehouses. For the site selection problem of emergency material warehouses, the triangular fuzzy numbers are respectively demand of the demand node, the distance between the warehouse and demand node and the cost of the warehouse, a bi-objective programming model was established with minimum total cost of the system and minimum distance between the selected emergency material warehouses and the demand node. Using the theories of fuzzy numbers, the fuzzy programming model was transformed into a determinate bi-objective mixed integer programming model and a heuristic algorithm for this model was designed. Then, the algorithm was proven to be feasible and effective through a numerical example. Analysis results show that the location of emergency material warehouse depends heavily on the values of degree a and weight wl. Accurate information of a certain emergency activity should be collected before making the decision.
文摘Based on the fuzzy characters of eco-environmental quality conception and classification standards, the incompatibility of evaluation indexes, the statistical fluctuation of index values, an information entropy fuzzy matter-element model for evaluating regional eco-environmental quality is proposed by way of comprehensively utilizing such theories as information theory, fuzzy sets and matter-element theory, etc. As a case, the model established here is used to evaluate the eco-environmental quality of Lake Chaohu basin. In the case, the eco-environmental quality standards and the evaluated schemes are indicated as matter-elements, together. Through constructing compound fuzzy matter-element, probability compound fuzzy matter-element and self-information compound fuzzy matter- element, the information entropy of each matter-element （including evaluated schemes and classification standards） is calculated in the end. According to these obtained information entropy values, the evaluated schemes can be not only arranged in quality state order but also classified by classification standards .Study result shows that information entropy fuzzy matter-element model is suitable for regional eco-environmental quality assessment.
