The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluatio...The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluation method can consider these two uncertainties to produce more objective and reasonable evaluation results. In this paper, we propose a combination evaluation method with two main parts:(1) the use of fuzzy comprehensive evaluation and gray correlation analysis as submodels with which to consider the fuzzy and gray uncertainties and(2) the establishment of a combination model based on minimum bias squares. In addition, using this method, we evaluate the water quality of a ditch in a typical rice–wheat system of Yixing city in the Taihu Lake Basin during three rainfall events. The results show that the ditch water quality is not good and we found the chemical oxygen demand to be the key indicator that affects water quality most significantly. The proposed combination evaluation method is more accurate and practical than single-factor evaluation methods in that it considers the uncertainties of fuzziness and grayness.展开更多
Combined Reliability distribution with correlation analysis,a new method has been proposed to make Reliability distribution where considering the elements about structure correlation and failure correlation of subsyst...Combined Reliability distribution with correlation analysis,a new method has been proposed to make Reliability distribution where considering the elements about structure correlation and failure correlation of subsystems.Firstly,we make a sequence for subsystems by means of TOPSIS which comprehends the considerations of Reliability allocation,and introducing a Copula connecting function to set up a distribution model based on structure correlation,failure correlation and target correlation,and then acquiring reliability target area of all subsystems by Matlab.In this method,not only the traditional distribution considerations are concerned,but also correlation influences are involved,to achieve supplementing information and optimizing distribution.展开更多
针对标准逼近理想解排序法(technique for order preference by similarity to ideal solution,TOPSIS)在雷达干扰效果评估中存在受数据波动影响和对数据规律分析不充分的问题,提出了一种改进的TOPSIS法。该方法结合TOPSIS法和灰色关联...针对标准逼近理想解排序法(technique for order preference by similarity to ideal solution,TOPSIS)在雷达干扰效果评估中存在受数据波动影响和对数据规律分析不充分的问题,提出了一种改进的TOPSIS法。该方法结合TOPSIS法和灰色关联分析理论对原始数据进行分析,并组合2种方法的评估结果作为最终的评估结果,弥补了TOPSIS法在雷达干扰效果评估中的缺陷,仿真实验验证了该方法的有效性。展开更多
基金supported by the National Key Research and Development Program of China (No. 2017YFC0405006)the Innovative Research Groups of the National Natural Science Foundation of China (No. 51621092)the Natural Science Foundation of Tianjin (No. 16JCYBJC23100)
文摘The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluation method can consider these two uncertainties to produce more objective and reasonable evaluation results. In this paper, we propose a combination evaluation method with two main parts:(1) the use of fuzzy comprehensive evaluation and gray correlation analysis as submodels with which to consider the fuzzy and gray uncertainties and(2) the establishment of a combination model based on minimum bias squares. In addition, using this method, we evaluate the water quality of a ditch in a typical rice–wheat system of Yixing city in the Taihu Lake Basin during three rainfall events. The results show that the ditch water quality is not good and we found the chemical oxygen demand to be the key indicator that affects water quality most significantly. The proposed combination evaluation method is more accurate and practical than single-factor evaluation methods in that it considers the uncertainties of fuzziness and grayness.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51175222,51275205)
文摘Combined Reliability distribution with correlation analysis,a new method has been proposed to make Reliability distribution where considering the elements about structure correlation and failure correlation of subsystems.Firstly,we make a sequence for subsystems by means of TOPSIS which comprehends the considerations of Reliability allocation,and introducing a Copula connecting function to set up a distribution model based on structure correlation,failure correlation and target correlation,and then acquiring reliability target area of all subsystems by Matlab.In this method,not only the traditional distribution considerations are concerned,but also correlation influences are involved,to achieve supplementing information and optimizing distribution.
文摘针对标准逼近理想解排序法(technique for order preference by similarity to ideal solution,TOPSIS)在雷达干扰效果评估中存在受数据波动影响和对数据规律分析不充分的问题,提出了一种改进的TOPSIS法。该方法结合TOPSIS法和灰色关联分析理论对原始数据进行分析,并组合2种方法的评估结果作为最终的评估结果,弥补了TOPSIS法在雷达干扰效果评估中的缺陷,仿真实验验证了该方法的有效性。
