共查询到20条相似文献,搜索用时 91 毫秒
1.
2.
3.
4.
基于GRA-DEA模型的有关农民收入的九城市的评价 总被引:1,自引:0,他引:1
王有文 《数学的实践与认识》2018,(6)
有关农民收入,文章以山西省九个城市为例进行了评价.首先用灰色关联分析法分析了2016年这些城市的有关数据,筛选出影响农民收入的主要因素;其次构建了指标体系,利用数据包络分析法对有关农民收入九个城市进行了DEA有效性评价;再次对非DEA有效的城市,借助投影公式探索了改进方法;最后得出了九城市分为两类的结论,提出了针对性的建议. 相似文献
5.
6.
7.
本文从实验事实出发,对含有共轭三键的共轭高聚物——聚丁二炔的掺杂及电导的特点进行了详细的分析;对聚丁二炔晶体掺杂的机制进行了初步的探讨;从结构相变的角度出发,提出了一个掺杂模型,并从能量的角度估算了由于掺杂引起链段结构改变所需的能量,较好地解释了聚丁二炔晶体掺杂未取得成功的原因. 相似文献
8.
10.
本文首先介绍了半群、群的定义,研究了自然数n取何值时,通过定义相应的代数运算,使得它的因子集构成半群、群,从而为半群的代数理论提供了一个有趣的实例. 相似文献
11.
12.
13.
K. I. Ivanov 《Mechanics of Composite Materials》1976,12(3):452-457
The "freezing" and "defreezing" temperature limits of an optically active material based on an epoxy resin have been experimentally investigated. A method of determining the mean value of the optical coefficient when the material is heated on the "freezing" temperature range is considered. The lower "defreezing" temperature limit has been experimentally established. The results of the investigation are presented in the form of graphs.Translated from Mekhanika Polimerov, No. 3, pp. 501–506, May–June, 1976. 相似文献
14.
15.
在利用"准最优基"简化单纯形法的求解过程的基础上,采用matlab将"准最优基"方法程序化,并采用程序进行了模型.求解原采用两阶段法求解的线性规划问题,用"准最优基"方法,不必加入人工变量,改两阶段为一阶段,简化了求解过程,并针对只能将其目标函数系数为正的变量进基、约束条件都为正的局限性进行了探讨."准最优基"方法对目标函数的系数有正有负的情况,约束条件的系数有正有负的情况都适用.借助"bland法则"的思想,按下标顺序进基取代变量强度系数进基,得出了同样的结果,并对E.Beale的循环例子进行计算,一步得出最优解."准最优基"方法既可以提高运算速度,同时具有很好的适用性. 相似文献
16.
Let G be the group "ax + b" of affine transformations of the line and let U be a neighbourhood of 1 in G. It is proved that there is another neighborhood V of 1 such that to each finite sequence g1,...,gn V there corresponds a sequence of signs 1,...,n = ±1 with
U for k = 1,...,n. This implies that G satisfies the following analogue of the Dvoretzky-Hanani theorem: to each sequence
converging to 1 in G there corresponds a sequence of signs k = ±1 such that the infinite product
is convergent. 相似文献
17.
Houssein El Turkey 《Journal of Pure and Applied Algebra》2018,222(1):181-190
The complexity of a module is the rate of growth of the minimal projective resolution of the module while the z-complexity is the rate of growth of the number of indecomposable summands at each step in the resolution. Let () be the type II orthosymplectic Lie superalgebra of types B or D. In this paper, we compute the complexity and the z-complexity of the simple finite-dimensional -supermodules. We then give these complexities certain geometric interpretations using support and associated varieties. 相似文献
18.
The fourth order average vector field (AVF) method is applied to solve
the "Good" Boussinesq equation. The semi-discrete system of the "good" Boussinesq
equation obtained by the pseudo-spectral method in spatial variable, which is a
classical finite dimensional Hamiltonian system, is discretized by the fourth order
average vector field method. Thus, a new high order energy conservation scheme of
the "good" Boussinesq equation is obtained. Numerical experiments confirm that the
new high order scheme can preserve the discrete energy of the "good" Boussinesq
equation exactly and simulate evolution of different solitary waves well. 相似文献
19.
首先探讨了运输问题“悖论”存在的条件和表上作业法的调整方法,然后指出了通过运输问题数学模型挖潜的方法,最后给出了“多反而少”现象存在的对偶条件。 相似文献
20.
首先探讨了运输问题"悖论"存在的条件和表上作业法的调整方法,然后指出了通过运输问题数学模型挖潜的方法,最后给出了"多反而少"现象存在的对偶条件. 相似文献