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本文首次研究时间尺度上一类新的二阶具有阻尼项的非线性时滞中立型动力方程的振动性的问题.利用时间尺度上的微积分理论、Riccati变换和不等式技巧的方法,获得方程振动的一些新的结果,推广已有文献的结果,丰富了三阶时滞动力方程的振动性.最后,通过例子验证了相关的结果. 相似文献
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《数学的实践与认识》2020,(4)
研究时间尺度上三阶非线性中立型分布时滞动力方程的振动性,利用广义Riccati变换和不等式技巧,建立了一个保证该方程每一个解振动或者收敛于零的充分性定理.本文所得定理推广和改进了已有文献中的相应结果. 相似文献
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《应用数学学报》2020,(3)
伴随着科学技术的发展,时间尺度上动力方程的振动性研究在诸如种群动力学模型和电子工程、量子力学和航空航天科技工程中的Keller振荡模型的应用中有着越来越重要的作用.近年来,对时间尺度上二阶动力方程的研究已有许多成果,但对三阶动力方程的研究相对不够完善,因此对三阶动力方程振动性和渐进性的研究具有重要意义.本文研究一类时间尺度上三阶非线性中立型Emden-Fowler时滞动力方程的振动性和渐近性,利用Riccati变换及不等式技巧,建立了该类方程几个新的Leighton型,Kemenev型和Philos型振动准则,推广,改进和统一了已有文献中包括该类微分方程和差分方程的相关结果,并给出实例展示了本文主要结论的效果. 相似文献
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利用广义Riccati技巧和积分平均技巧,研究具有强迫项的二阶非线性时滞微分方程的振动性态,得到了这类方程振动的若干新的区间判别准则. 相似文献
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具连续变量的二阶非线性差分方程振动和非振动的充要条件 总被引:2,自引:0,他引:2
研究了一类具有连续变量的二阶非线性差分方程的振动性质,利用Banach空间的不动点原理和一些分析技巧,得到了这类方程存在非振动解的充分必要条件,并得到了这类方程振动的充分必要条件,同时给出了说明定理应用的例子. 相似文献
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Jogi Henna 《Annals of the Institute of Statistical Mathematics》2005,57(4):655-664
An estimator of the number of components of a finite mixture ofk-dimensional distributions is given on the basis of a one-dimensional independent random sample obtained by a transformation
of ak-dimensional independent random sample. A consistency of the estimator is shown. Some simulation results are given in a case
of finite mixtures of two-dimensional normal distributions. 相似文献
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N/Kbe a Galois extension of number fields with finite Galois group G.We describe a new approach for constructing invariants of the G-module structure of the K groups of the ring of integers of N in the Grothendieck group of finitely generated projective Z[G]modules. In various cases we can relate these classes, and their function field counterparts, to the root number class of Fröhlich and Cassou-Noguès. 相似文献
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Piotr Je¸drzejewicz 《代数通讯》2013,41(4):1500-1508
Let A be a UFD of characteristic p > 0, let 𝒵 be a set of some eigenvectors of a derivation of A. We prove, under some additional assumptions, a necessary and sufficient condition for 𝒵 to be a p-basis of the minimal ring of constants containing 𝒵. The main preparatory result is the unique decomposition theorem with respect to a factor from a given subalgebra containing Ap. 相似文献
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有资格限制的指派问题的求解方法 总被引:3,自引:0,他引:3
在实际的指派工作中,常会遇到某个人有没有资格去承担某项工作的问题,因此,本建立了有资格限制的指派问题的数学模型。在此数学模型中,将效益矩阵转化为判定矩阵,由此给出了判定此种指派问题是否有解的方法;在有解的情况下,进一步将效益矩阵转化为求解矩阵,从而将有资格限制的指派问题化为传统的指派问题来求解。最后给出了一个数值例子来说明这样的处理方法是有效的。 相似文献
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本文在LF拓扑空间中建立了L-fuzzy集网的弱收敛(R-收敛)概念,应用文[4]中的R-闭包,系统讨论了它们的性质,证明了等式RlimA_n=∧(∨A_m)_R和RlimA_n=A_n=∧(∨A_m)_R并且给出了L-fuzzy集网与其子网之间的关系。 相似文献
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We study the nilpotency of the sums of all coefficients of some sorts of products of polynomials over reversible, IFP, and NI rings, and introduce an SCN ring as a generalization. We characterize SCN rings in relation with related ring properties, and also provide several useful properties and ring extensions of SCN rings. 相似文献
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Rodney Y. Sharp 《Proceedings of the American Mathematical Society》2003,131(10):3009-3017
It is a well-known result of M. Brodmann that if is an ideal of a commutative Noetherian ring , then the set of associated primes of the -th power of is constant for all large . This paper is concerned with the following question: given a prime ideal of which is known to be in for all large integers , can one identify a term of the sequence beyond which will subsequently be an ever-present? This paper presents some results about convergence of sequences of sets of associated primes of graded components of finitely generated graded modules over a standard positively graded commutative Noetherian ring; those results are then applied to the above question.
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设P1,P2,……,Pt是几乎覆盖图G的l条不相交的路,s是没有被这些路覆盖的孤立点数.本证明:(i)匹配多项式μ(G,x)的非零根的重数最多是l,零根的重数最多l s。(ii)对于不含三角形的n阶图G,伴随多项式h(G,x)的非零根的重数最多是l,零根的重数最多是1/2(n l s).(iii)对一种含三角形的所谓A型图,(ii)也成立. 相似文献
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任意矩阵的特征值的扰动估计 总被引:1,自引:0,他引:1
设A和B是两个任意的n阶方阵,其特征值分别为{λ_1,…,λ_n}和{μ_1,…,μ_n}.本文对此两组特征值的如下“距离”的界给出了若干估计: B对于A的谱改变量 A与B的特征值的改变量这里的结果包含了Bauer-Fike定理,并且优于Kahan-Parlett/Jiang定理及Chu,施和肖所得出的结果. 相似文献
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Let L be the Euclidean functional with p-th power-weighted edges. Examples include the sum of the p-th power-weighted lengths of the edges in minimal spanning trees, traveling salesman tours, and minimal matchings. Motivated
by the works of Steele, Redmond and Yukich (Ann. Appl. Probab. 4, 1057–1073, 1994, Stoch. Process. Appl. 61, 289–304, 1996) have shown that for n i.i.d. sample points {X
1,…,X
n
} from [0,1]
d
, L({X
1,…,X
n
})/n
(d−p)/d
converges a.s. to a finite constant. Here we bound the rate of convergence of EL({X
1,…,X
n
})/n
(d−p)/d
.
Y. Koo supported by the BK21 project of the Department of Mathematics, Sungkyunkwan University.
S. Lee supported by the BK21 project of the Department of Mathematics, Yonsei University. 相似文献