共查询到20条相似文献,搜索用时 62 毫秒
1.
拟Raabe判别法是新近提出的关于正项级数收敛性的一种比较细致的判别法.对通项递减的正项级数来说,此判别法强于传统的Raabe判别法与Gauss判别法.通过对拟Raabe判别法与另一个细致的判别法——拟对数判别法强弱关系的探讨,得出了后一判别法强于前者的结论. 相似文献
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正项级数的Raabe对数判别法 总被引:1,自引:0,他引:1
在正项级数敛散性Raabe判别法和第一对数判别法的基础上,以P-级数作为比较标准,讨论了第二对数判别法,并且证明了Raabe判别法和第二对数判别法的等价性. 相似文献
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讨论包络和奇解的判断问题,通过分析c-判别曲线上切线斜率的存在性,明确p-判别曲线中p的含义,得出通解曲线族中的曲线只有在c-判别曲线上每一点处存在切线斜率时,c-判别曲线才有可能是包络,否则c-判别曲线必定不是包络,另外在求奇解时,p-判别曲线中的p必须等于p-判别曲线的斜率,否则p-判别曲线必定不是奇解. 相似文献
4.
某些常见的重要的正项级数判别法可以进行统一表述,得到的同一表达形式,可用以比较现有多种正项级数判别法的不同精密度。可以认为,该判别法包含了目前常见的正项级数收敛性的判别法,其它判别法只是该判别法的特殊情况。 相似文献
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仿射框架是小波理论中很基本的概念.熟知的关于仿射框架的Daubechies判别法引用了由绝对值| (ajω) (ajω lT)|算出的量来作判别.在本文建立的新判别法中引用了由(ajω) (ajω lT)的适当组合的代数和算出的量来作判别.当为偶函数时,新的判别法优于Daubechies判别法. 相似文献
7.
基于正项级数的比较判别法和p-级数的敛散性,给出一个与D’Alembert判别法和Cauchy判别法平行的判别正项级数敛散性的方法.并通过实例对所给判别法的可行性进行检验,发现它是已有方法的一个有效补充. 相似文献
8.
经过计算和逻辑推理,提出两种判别范围较大的正项级数判敛法,即广义高斯判别法及广义拟对数判别法,并对这两个判别法进行了比较. 相似文献
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艾斯卡尔.阿布力米提 《数学通报》2001,(3):34-34
直接使用Cauchy判别法或者D'alembert判别法来判别数项级数的敛散性时,有时计算极限难度大.为了计算极限简单,本文提出灵活使用Cauchy判别法和D'alembert判别法的方法. 相似文献
11.
James Ting-Ho Lo 《Journal of Global Optimization》2010,46(2):317-318
The main results reported in this paper are two theorems concerning the use of a newtype of risk-averting error criterion
for data fitting. The first states that the convexity region of the risk-averting error criterion expands monotonically as
its risk-sensitivity index increases. The risk-averting error criterion is easily seen to converge to the mean squared error
criterion as its risk-sensitivity index goes to zero. Therefore, the risk-averting error criterion can be used to convexify
the mean squared error criterion to avoid local minima. The second main theorem shows that as the risk-sensitivity index increases
to infinity, the risk-averting error criterion approaches the minimax error criterion, which is widely used for robustifying
system controllers and filters. 相似文献
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Huidong Xu Guilin Wen Qixiang Qin Huaan Zhou 《Communications in Nonlinear Science & Numerical Simulation》2013,18(8):2120-2128
Hopf–Hopf bifurcation is one of typical codimension-two bifurcations, which requires some rigid bifurcation conditions and occurs only in high-dimension systems. In this paper, a new critical criterion of this bifurcation is presented for a general discrete time system. Unlike the corresponding classical critical criterion (or the bifurcation definition), the new criterion is composed of a series of algebraic conditions explicitly expressed by the coefficients of the characteristic polynomial, which does not depend on eigenvalue computations of Jacobian matrix. This characteristic gives the advantage of the proposed criterion which is more convenient and efficient for detecting the existence of this type of codimension-two bifurcation or exploring the parameter mechanism of the bifurcation than the corresponding classical criterion. The equivalence between the proposed criterion and the corresponding classical criterion is rigorously proved. The bifurcation design problem of a three-degree-of-freedom vibro-impact system is used as example to show the effectiveness of the proposed criterion. 相似文献
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本文提出预测复合材料中裂纹方向的比应变能密度准则,并将Tsai-Hill与Norris准则扩展来预测复合材料中的开裂方向.用这三个准则预测了具有各种不同纤维方向的单向纤维复合材料的裂纹扩展方向,预测结果与现有的比正应力准则和应变能密度准则进行了对比. 相似文献
15.
The choice of weights in frequentist model average estimators is an important but difficult problem. Liang et al. (2011) suggested a criterion for the choice of weight under a general parametric framework which is termed as the generalized OPT (GOPT) criterion in the present paper. However, no properties and applications of the criterion have been studied. This paper is devoted to the further investigation of the GOPT criterion. We show that how to use this criterion for comparison of some existing weights such as the smoothed AIC-based and BIC-based weights and for the choice between model averaging and model selection. Its connection to the Mallows and ordinary OPT criteria is built. The asymptotic optimality on the criterion in the case of non-random weights is also obtained. Finite sample performance of the GOPT criterion is assessed by simulations. Application to the analysis of two real data sets is presented as well. 相似文献
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Vimal Singh 《Journal of Difference Equations and Applications》2013,19(12):1255-1265
Using Lyapunov's direct method, a novel frequency-domain criterion for the elimination of limit cycles in a class of digital filters using single saturation nonlinearity is derived. The criterion turns out to be a generalization and improvement over an earlier criterion due to Kar and Singh. An example showing the effectiveness of the criterion is given. A graphical interpretation of a simplified version (involving one free parameter) of the criterion is discussed. 相似文献
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Vimal Singh 《Applied mathematics and computation》2011,218(8):4305-4311
A new criterion for the global asymptotic stability of discrete-time systems in a state-space realization utilizing saturation nonlinearities is presented. The form of the criterion is unconventional in that it offers the flexibility of using even an unsymmetric Lyapunov matrix P. A recently reported criterion is shown to be a special case of the present criterion. An example shows the effectiveness of the new criterion. 相似文献
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Vimal Singh 《Nonlinear Analysis: Real World Applications》2013,14(3):1503-1510
A novel criterion for the elimination of overflow oscillations in 2-D state-space digital filters described by the Roesser model employing two’s complement overflow arithmetic is presented. The criterion takes the form of linear matrix inequality (LMI) and, hence, is computationally tractable. The criterion is a generalization and improvement over an earlier criterion. An example shows the effectiveness of the new criterion. 相似文献
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《Journal of Computational and Applied Mathematics》2002,149(1):335-339
There are three famous criteria for the prediction on the direction of crack extension: maximum energy release rate criterion, local symmetric criterion and maximum stress criterion. It has already been proved that these criteria are different. In this paper, we show how to measure the difference between maximum energy release rate criterion and maximum stress criterion. The results in this paper and special solutions in Amestoy and Leblond (Internat. J. Solids Struct. 29 (1992) 465) indicate that it is enough to use the maximum stress criterion for the numerical prediction of crack path, if the stress intensity factor of the shearing mode is not too big. 相似文献
20.
Xianping Guo 《Mathematical Methods of Operations Research》1999,49(1):87-96
In this paper, we consider the nonstationary Markov decision processes (MDP, for short) with average variance criterion on a countable state space, finite action spaces and bounded one-step rewards. From the optimality equations which are provided in this paper, we translate the average variance criterion into a new average expected cost criterion. Then we prove that there exists a Markov policy, which is optimal in an original average expected reward criterion, that minimizies the average variance in the class of optimal policies for the original average expected reward criterion. 相似文献