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1.
基于同异反态势排序的学生成绩分析   总被引:32,自引:1,他引:31  
同异反态势排序是根据同异反联系数 a+bi+cj中 a、b、c大小关系而进行的一种排序。当把学生成绩用同异反联系数表示之后 ,可对照同异反态势排序表来研究其中的某些规律  相似文献   

2.
在B型关联分析基础上给出了同异反同一度和综合同一度的概念,论证了同异反动态关联分析的性质及其求解方法。为研究事物的发展态势提供了一种动态分析方法  相似文献   

3.
对洪灾系统作综合风险研究,已是防洪减灾理论发展的一大趋势.在洪灾风险的同异反综合分析方法(概念模型)的基础上,以不确定性系数i对风险的影响为切入点,并进行适当的扩展与变换,将同异反综合分析方法进一步深入,建立了洪灾综合风险分析的模拟模型框架,初步得到了洪灾综合风险分析的可行途径.  相似文献   

4.
基于SPA的学生成绩态势分析   总被引:23,自引:0,他引:23  
SPA中的同异反态势排序可以根据需要作不同层次的展开。当把学生成绩作优、良、中、差四档次划分时,可对照同异反态势排序的一种展开来研究学生成绩中蕴含的信息。  相似文献   

5.
张发明 《应用数学》1998,11(2):9-16
利用指数二分性理论和泛函分析方法,我们研究了自治奇摄动系统的同,异宿轨道的存在性,给出了高维奇摄动系统从退化系统分支出同异宿轨道的Mel-nikov型函数。  相似文献   

6.
研究较一般的高维退化系统的同宿、异宿轨道分支问题.利用推广的Melnikov函数、横截性理论及奇摄动理论,对具有鞍—中心型奇点的带有角变量的奇摄动系统,在角变量频率产生共振的情况下,讨论其同宿、异缩轨道的扰动下保存和横截的条件.推广和改进了一些文献的结果。  相似文献   

7.
空间同宿环和异宿环的稳定性   总被引:7,自引:0,他引:7  
冯贝叶 《数学学报》1996,39(5):649-658
关于平面同(异)宿环的稳定性已有不少文献讨论过,但关于空间同(异)宿环的稳定性尚没有任何结果.本文在可定义回复映射的条件下给出了同(异)宿环在其部分邻域中是渐近稳定的判据.这些结果在某种意义下是平面系统相应结果的推广,包括并推广了[2],[3]的结果.本文最后讨论了Lorenz系统同宿环和三种群竞争系统异宿环的稳定性,所得结果和Sparrow与May等的数值结果相吻合.  相似文献   

8.
为了优化同异反(Identical-Discrepant-Contrary,简称IDC)灰色相关分析中同异反趋势划分方法,提高同异反趋势划分结果的精度,文章在分析两种传统划分方法存在不足的基础上,对其进行改进,提出了均分迭代划分法和回归系数比值划分法,并结合土壤中有机质含量和砷含量相关性的实例,对改进后的两种方法进行数值模拟.结果表明:改进后的两种划分方法得到结果的可靠度均较高,采用均分迭代划分法得到结果的可靠度为70%,采用回归系数比值划分法得到结果的可靠度为55%,略低于前者,这是因为土壤有机质含量中存在"异常"数据,对回归系数影响较大,降低了回归系数比值划分结果的精度.  相似文献   

9.
洪灾综合风险分析方法讨论(Ⅰ)——基于集对分析理论   总被引:1,自引:0,他引:1  
随着社会经济的发展及人们对洪水灾害认识的深入,洪灾风险的研究从单一风险转向综合风险,将是防洪减灾理论发展的必然趋势.根据洪灾风险的特性,引入信息的整体性原理,并应用集对分析理论对洪灾风险系统进行确定不确定分析,首次提出了洪灾系统风险的同异反分析方法.该方法将干旱、洪涝及其风险信息综合体现在洪水灾害系统的联系度中,从而为进一步开展详尽的综合风险分析奠定了理论基础.  相似文献   

10.
工业企业经济和环境综合效益的集对分析   总被引:1,自引:0,他引:1  
应用集对分析中的同异反态势排序法进行了重点工业污染源资源消耗和排污状况分析.实例分析表明,该方法和评价模型具有简单实用的特点.  相似文献   

11.
两刚性平行平面之间粘附长条弹性体(其横截面为矩形),在上下两面相反方向切向力的作用下,弹性体将发生变形.在导出这种变形的数学模型的基础上,给出了一种新的差分解法.对于具有奇性的边界条件,进行了详细的分析和推导,给出了一种合理而有效的新的离散边界条件.模拟计算表明,其结果与定性分析相吻合.因此对该类问题的研究提供了新的实用的数值解法和数值分析方法.  相似文献   

12.
Chaos synchronization and parameter identification for loudspeaker systems   总被引:3,自引:0,他引:3  
The identical two-degrees-of-freedom loudspeaker systems are discussed for synchronization of chaos in this paper. Two methods are used to synchronize two identical chaotic systems with different initial condition: the adaptive control and the Gerschgorin's theorem. Finally we research the parameter identification for two identical two-degrees-of-freedom loudspeaker systems by adaptive control and random optimization method.  相似文献   

13.
Present study deals with the steady flow and heat transfer of a non‐Newtonian Reiner‐Rivlin fluid between two coaxially rotating infinite disks. Using similarity transformations, the governing equations are reduced to a set of nonlinear, highly coupled ordinary differential equations and by means of an effective analytical method called homotopy analysis method; analytical solutions are constructed in series form. Different cases, such as, when one disk is at rest and the other is rotating with constant angular velocity, two disks rotating with different angular velocities in same as well as opposite sense, two disks rotating with same angular velocities in opposite sense, are discussed. The effects of non‐Newtonian parameter, Reynolds number, are also discussed, and results are presented graphically.  相似文献   

14.
Nonlinear control is an effective method for making two identical chaotic systems or two different chaotic systems be synchronized. However, this method assumes that the Lyapunov function of error dynamic (e) of synchronization is always formed as V (e) = 1/2eTe. In this paper, modification based on Lyapunov stability theory to design a controller is proposed in order to overcome this limitation. The method has been applied successfully to make two identical new systems and two different chaotic systems (new system and Lorenz system) globally asymptotically synchronized. Since the Lyapunov exponents are not required for the calculation, this method is effective and convenient to synchronize two identical systems and two different chaotic systems. Numerical simulations are also given to validate the proposed synchronization approach.  相似文献   

15.
This paper deals with two criteria for selection of variables for the discriminant analysis in the case of two multivariate normal populations with different means and a common covariance matrix. One is based on the estimated error rate of misclassification. The other uses Akaike's information criterion. The asymptotic distributions and error rate risks of the criteria are obtained. The result will prove that the two criteria are asymptotically equivalent in the sense of their asymptotic distributions and error rate risks being identical.  相似文献   

16.
优化路问题的代数方法—论动态规划(Ⅱ)   总被引:2,自引:0,他引:2  
秦裕瑗 《应用数学》1994,7(4):410-416
本文用同一思路求解多阶段有向图中三种优化路问题:最优路、N阶最优路及多指标Pareto优化路问题,它们都服从嘉量原理,都用同一个代数公式表达它们的嘉量,并可在同一种表格中进行计算,只是所在半域不同,以本文的方法讨论动态规划中一些离散决定型典型应用问题,其提法、建模思路以及求解过程都有可观的扩大与改善。  相似文献   

17.
In this paper, a colored community network model with different order nodes dynamics is introduced for the first time. The color of nodes or edges are assumed to be identical if they belong to the same community and nonidentical if they belong to different communities. The color of edges between any pair of communities are assumed to be identical if they connect the same pair of communities and nonidentical if they connect different pair of communities. Further, the order of the node dynamics in different communities can be totally different. Firstly, based on the Lyapunov stability theory, adaptive feedback controllers are designed for achieving cluster synchronization. Secondly, periodically intermittent controllers are designed for achieving cluster synchronization and the synchronization conditions are derived by using mathematical induction method and the analysis technique. Finally, several numerical examples are provided to illustrate the effectiveness of the derived theoretical results.  相似文献   

18.
This paper proposes optimum ramp accelerated life test (ALT) of m identical repairable systems using non-homogeneous power law process (PLP) under failure truncated case. An ALT with linearly increasing stress is a ramp test. In particular, a ramp test with two different linearly increasing stresses is a simple ramp test. The optimum ramp test with different stress rates is formulated by determining the proportions of test systems allocated to each stress rate using D-optimality criterion. D-optimality criterion minimizes the reciprocal of the determinant of the Fisher information matrix of the model parameters. The method developed is illustrated using two stress rates and three stress rates. It has been found that it takes much longer to obtain same estimated expected no. of failures at baseline condition than at stress levels.  相似文献   

19.
利用互联网数据,在合理假设的前提下,给出了上海世博会对上海旅游业影响的定量评估.利用线性加权综合分析法建立综合评价指标的线性模型,并从两个不同的角度,分别得出上海世博会对上海旅游业的综合评价指标,同时建立灰色系统预测模型,利用2006至2009年的评价指标,对2010年的评价指标进行预测.通过实际的增长值与预测增长值的...  相似文献   

20.
The power-series approximation method for solving regular perturbation problems is reexamined to show why the method works. As another way to approach these problems, the variational perturbation technique is described. Although the assumptions on which each method is based and the mechanism of deriving their differential equations are different, the system of differential equations developed by each method is identical.Dedicated to R. Bellman  相似文献   

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