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1.
In this paper, we mainly study zeros and poles of the forward differences Δnf(z), where f(z) is a finite order meromorphic function with two Borel exceptional values. 相似文献
2.
刘春月 《数学的实践与认识》2016,(18):69-75
配送企业通过结成联盟、实施共同配送可以集约资源,降低各配送成本,改善社会效益.针对联盟协作下配送企业间的利润分配问题构建收益分配的基础模型,引入风险,资源,商誉、品牌、市场地位等因素进行二次修正,用数值模拟的方法,揭示共同配送联盟利益分配机理.研究结论表明,修正后的利益分配机制,能有效地避免共同配送成员"搭便车"现象及平均主义思想,更能够体现分配的科学性.对促进配送企业积极参与共同配送、保持物流联盟的稳定具有重要意义. 相似文献
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多元极值分布参数的最大似然估计与分步估计 总被引:7,自引:0,他引:7
本文考虑多元极值分布的参数估计,给出了分步估计渐近协差阵的近似表示,并对维数P=2,5及相关参数α=0.001,0.01;0.1(0.2),0.9;0.99,0.999的各种组合,计算了分步估计关于最大似然估计的渐近效率,分析了各种参数及维数对渐近效率的影响.分步估计是一种合理、简单而且有较强实用意义的估计方法. 相似文献
5.
Alec Stephenson 《Extremes》2003,6(1):49-59
Methods are given for simulating from symmetric and asymmetric versions of the multivariate logistic distribution, and from other multivariate extreme value distributions based on the well known logistic model. We consider two general approaches. The first approach uses transformations to derive random variables with a joint distribution function from which it is easy to simulate. The second approach derives from a specification of conditionally independent marginal components, conditioning on positive stable random variables. This specification extends to models of nested or hierarchical type and leads to an efficient way of incorporating marginal censoring. The algorithms presented in Sections 2 and 3 are available on request from the author. They are also included in the R (Ihaka and Gentleman, 1996) package evd (Stephenson, 2002), which is available from http://www.maths.lancs.ac.uk/~stephena/. 相似文献
6.
Let U
1, U
2, ... be a sequence of independent random points taking values in a measurable space (S, Σ) according to a common probability P and let
R be a symmetric, Borel/
-measurable function. Let H
n
= max{h(U
i
,U
j
): 1≤ i < j≤ n} denote the maximum h-value over pairs of distinct points from U
1,U
2,...,U
n
. Assumptions on the distribution of h(U
1,·) are provided under which a continuous function of H
n
converges in law to an extreme-value distribution upon suitable rescaling. The work is complementary to that appearing in
Appel et al. (1999) J. Theor. Probab. 12, 27–47. on the almost-sure limiting behavior of H
n
. In the first of two examples, the main result applied to the case of i.i.d. points distributed uniformly on the surface
of a unit hypersphere in R
d
provides the limiting distribution of the maximum pairwise distance (chord length) among the first n of the points. The second example exhibits the limiting distribution of the minimum pair-wise distance among the first n of i.i.d. uniform points in a compact subset of R
d
.
相似文献
7.
Pareto分布中门槛值的确定及其在股票市场中的应用 总被引:1,自引:0,他引:1
本文根据Pareto分布与两参数指数分布之间的相互关系,利用两参数指数分布的拟合优度检验统计量给出了确定Pareto分布的门槛值的一种方法。利用道琼斯指数和上证综合指数的收益率序列说明所给方法,结果表明所给方法优于现有方法。 相似文献
8.
Paolo Tilli 《Linear and Multilinear Algebra》2013,61(2-3):147-159
An elementary and direct proof of the Szegö formula is given, for both eigen and singular values. This proof, which is based on tools from linear algebra and does not rely on the theory of Fourier series, simultaneously embraces multilevel Toeplitz matrices, block Toeplitz matrices and combinations of them. The assumptions on the generating function f are as weak as possible; indeedf is a matrix-valued function of p variables, and it is only supposed to be integrable. In the case of singular values f(x), and hence the block p-level Toeplitz matrices it generates, are not even supposed to be square matrices. Moreover, in the asymptotic formulas for eigen and singular values the test functions involved are not required to have compact support. 相似文献
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本文通过两个统计年报表的例子验证了统计报表中的数据近似服从对数正态分布,并利用这一特点建立了对数线性模型,对统计报表中的异常值进行识别和对缺失值作出预测。 相似文献
11.
本文利用极值分布的一些特性和不动点原理,讨论了定数截尾情形下极值分布参数的估计问题,并提出了一种新的迭代算法;模拟结果显示,这种方法收敛速度快,且不受初始值选取的限制. 相似文献
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A.S. Al‐Fhaid S. Serra‐Capizzano D. Sesana M. Zaka Ullah 《Numerical Linear Algebra with Applications》2014,21(6):722-743
Let k( ? , ? ) be a continuous kernel defined on Ω × Ω, Ω compact subset of , , and let us consider the integral operator from into ( set of continuous functions on Ω) defined as the map is a compact operator and therefore its spectrum forms a bounded sequence having zero as unique accumulation point. Here, we first consider in detail the approximation of by using rectangle formula in the case where Ω = [0,1], and the step is h = 1 ∕ n. The related linear application can be represented as a matrix An of size n. In accordance with the compact character of the continuous operator, we prove that {An} ~ σ0 and {An} ~ λ0, that is, the considered sequence has singular values and eigenvalues clustered at zero. Moreover, the cluster is strong in perfect analogy with the compactness of . Several generalizations are sketched, with special attention to the general case of pure sampling sequences, and few examples and numerical experiments are critically discussed, including the use of GMRES and preconditioned GMRES for large linear systems coming from the numerical approximation of integral equations of the form (1) with and datum g(x). Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
14.
本文研究亚纯函数的值分布问题.利用值分布理论,获得了一个带精简密指量的模分布的不等式,改进了Xu和Yang等人的结果. 相似文献
15.
Let f(z) be a meromorphic function andΨbe the differential polynomial of f which satisfies the condition of N(r, f) N (r, 1/f) = S(r, f). We obtain several results about the zero point of theΨand those results extend and improve the results of Yang and Yi in this paper. 相似文献
16.
In this article,two uniqueness theorems of meromorphic mappings on moving targets with truncated multiplicities are proved. 相似文献
17.
Let F be a family of functions meromorphic in a domain D, let n ≥ 2 be a positive integer, and let a ≠ 0, b be two finite complex numbers. If, for each f ∈ F, all of whose zeros have multiplicity at least k + 1, and f + a(f^(k))^n≠b in D, then F is normal in D. 相似文献
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Let ƒ be a transcendental meromorphic function, a a nonzero finite complex number, and n ⩾ 2 a positive integer. Then ƒ + a(ƒ′)
n
assumes every complex value infinitely often. This answers a question of Ye for n = 2. A related normality criterion is also given.
This work was supported by the National Natural Science Foundation of China (Grant No. 10771076), the Natural Science Foundation
of Guangdong Province, China (Grant No. 07006700) and by the German-Israeli Foundation for Scientific Research and Development
(Grant No. G-809-234.6/2003) 相似文献