In order to evaluate the quality of water environment, the conception of entropy is applied in information science, and the entropy weight model is built to evaluate comprehensively water quality. The indexes weights ...In order to evaluate the quality of water environment, the conception of entropy is applied in information science, and the entropy weight model is built to evaluate comprehensively water quality. The indexes weights of water quality are determined by value of entropy. This kind of method is applied on evaluating water quality in the new water to be built. The result shows that the water quality in it which supply water is between grade Ⅲ and Ⅳ, and the result is similar to that of gray related method.展开更多
For the gray attributes of the equipment program and its difficulty to carry out the quantitative assessment of the equipment program information, the gray relation projection method is simply reviewed. Combining the ...For the gray attributes of the equipment program and its difficulty to carry out the quantitative assessment of the equipment program information, the gray relation projection method is simply reviewed. Combining the super-data envelopment analysis（DEA） model and the gray system theory, a new super-DEA for measuring the weight is proposed, and a gray relation projection model is established to rank the equipment programs. Finally, this approach is used to evaluate the equipment program. The results are verified valid and can provide a new way for evaluating the equipment program.展开更多
On the basis of the quasi-geostrophic vorticity equation,theoretical research has been down upon the evolution of the amplitude of solitary Rossby waves employing the perturbation method,and come to the conclusion tha...On the basis of the quasi-geostrophic vorticity equation,theoretical research has been down upon the evolution of the amplitude of solitary Rossby waves employing the perturbation method,and come to the conclusion that the evolution of the amplitude satisfies the variable coefficient Korteweg-de Vries(KdV) equation.展开更多
暴雨洪水管理模型(storm water management model,SWMM)的不确定参数在一定程度上影响着内涝模拟的精度,因此以中山市某研究区域为例,计算SWMM模型参数的初始值,采用最大互信息系数和偏相关系数探究短历时、长历时不同重现期下对径流总...暴雨洪水管理模型(storm water management model,SWMM)的不确定参数在一定程度上影响着内涝模拟的精度,因此以中山市某研究区域为例,计算SWMM模型参数的初始值,采用最大互信息系数和偏相关系数探究短历时、长历时不同重现期下对径流总量、出流总量、峰值流量和峰现时间敏感的参数,并利用熵权法确定2种方法的权重进行综合评价,结合综合分析得到的敏感参数和偏相关分析得到的变量之间的正负相关关系,选取8场历史降雨对模型进行率定与验证。结果表明:2种方法得到的各重现期下敏感参数并不完全一致;综合分析发现不同重现期要考虑的敏感参数略有不同,且各重现期最敏感参数与最大互信息系数的结果一致;P=10 a、20 a同一重现期不同降雨历时下敏感参数存在较大差异;模型模拟的管网井下液位的纳什效率系数均大于0.7,峰现时间误差均小于等于30 min,峰值相对误差的绝对值均小于3.5%。通过深入分析模型参数的不确定性,可提高参数率定效率和模型的准确度。展开更多
文摘In order to evaluate the quality of water environment, the conception of entropy is applied in information science, and the entropy weight model is built to evaluate comprehensively water quality. The indexes weights of water quality are determined by value of entropy. This kind of method is applied on evaluating water quality in the new water to be built. The result shows that the water quality in it which supply water is between grade Ⅲ and Ⅳ, and the result is similar to that of gray related method.
基金supported by the National Natural Science Foundation of China(7107307971222106+2 种基金70901069)the Research Foundation of the National Excellent Doctoral Dissertation of Chinathe Research Fund for the Doctoral Program of Higher Education(20133402110028)
文摘For the gray attributes of the equipment program and its difficulty to carry out the quantitative assessment of the equipment program information, the gray relation projection method is simply reviewed. Combining the super-data envelopment analysis（DEA） model and the gray system theory, a new super-DEA for measuring the weight is proposed, and a gray relation projection model is established to rank the equipment programs. Finally, this approach is used to evaluate the equipment program. The results are verified valid and can provide a new way for evaluating the equipment program.
基金supported by the Meteorological Special Project of China(GYHY200806005)the National Natural Sciences Foundation of China(40805028,40675039,40575036)the Key Technologies R&D Program of China(2009BAC51B04)
文摘On the basis of the quasi-geostrophic vorticity equation,theoretical research has been down upon the evolution of the amplitude of solitary Rossby waves employing the perturbation method,and come to the conclusion that the evolution of the amplitude satisfies the variable coefficient Korteweg-de Vries(KdV) equation.
