Based on the fuzziness and impreciseness of water environmental system, the fuzzy arithmetic was used to simulate the fuzzy and imprecise relations in modeling river water quality. By defining the parameters of water ...Based on the fuzziness and impreciseness of water environmental system, the fuzzy arithmetic was used to simulate the fuzzy and imprecise relations in modeling river water quality. By defining the parameters of water quality model as symmetrical triangular fuzzy numbers, a two-dimensional fuzzy water quality model for sudden pollutant discharge is established. From the fuzzy model, the pollutant concentrations, corresponding to the specified confidence level of a, can be obtained by means of the a-cut technique and arithmetic operations of triangular fuzzy numbers. Study results reveal that it is feasible in theory and reliable on calculation applying triangular fuzzy numbers to the simulation of river water quality.展开更多
The minimization of the profit function with respect to the decision variables is very important for the decision makers in the oil field industry.In this paper,a novel approach of the improved tabu search algorithm h...The minimization of the profit function with respect to the decision variables is very important for the decision makers in the oil field industry.In this paper,a novel approach of the improved tabu search algorithm has been employed to solve a large scale problem in the crude oil refinery industry.This problem involves 44 variables,36 constraints,and four decision variables which represent four types of crude oil types.The decision variables have been modeled in the form of fuzzy linear programming problem.The vagueness factor in the decision variables is captured by the nonlinear modified S-curve membership function.A recursive improved tabu search has been used to solve this fuzzy optimization problem.Tremendously improved results are obtained for the optimal profit function and optimal solution for four crude oil.The accuracy of constraints satisfaction and the quality of the solutions are achieved successfully.展开更多
基金the National Natural Science foundation of China (Grant No. 40672154)the Natural Science Foundation of Anhui Province (Grant No. 050450303).
文摘Based on the fuzziness and impreciseness of water environmental system, the fuzzy arithmetic was used to simulate the fuzzy and imprecise relations in modeling river water quality. By defining the parameters of water quality model as symmetrical triangular fuzzy numbers, a two-dimensional fuzzy water quality model for sudden pollutant discharge is established. From the fuzzy model, the pollutant concentrations, corresponding to the specified confidence level of a, can be obtained by means of the a-cut technique and arithmetic operations of triangular fuzzy numbers. Study results reveal that it is feasible in theory and reliable on calculation applying triangular fuzzy numbers to the simulation of river water quality.
文摘The minimization of the profit function with respect to the decision variables is very important for the decision makers in the oil field industry.In this paper,a novel approach of the improved tabu search algorithm has been employed to solve a large scale problem in the crude oil refinery industry.This problem involves 44 variables,36 constraints,and four decision variables which represent four types of crude oil types.The decision variables have been modeled in the form of fuzzy linear programming problem.The vagueness factor in the decision variables is captured by the nonlinear modified S-curve membership function.A recursive improved tabu search has been used to solve this fuzzy optimization problem.Tremendously improved results are obtained for the optimal profit function and optimal solution for four crude oil.The accuracy of constraints satisfaction and the quality of the solutions are achieved successfully.
