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1.
A family of distributions for which an unbiased estimator of a functiong(θ) of a real parameter θ can attain the second order Bhattacharyya lower bound is derived. Indeed, we obtain a necessary and sufficient condition for the attainment of the second order Bhattacharyya bound for a family of mixtures of distributions which belong to the exponential family. Furthermore, we give an example which does not satisfy this condition, but where the Bhattacharyya bound is attainable for a non-exponential family of distributions.  相似文献   

2.
Generalization of an Existence Theorem for Variational Inequalities   总被引:1,自引:0,他引:1  
By using the concept of exceptional family of elements, Zhao proposed a new existence theorem for variational inequalities over a general nonempty closed convex set (Ref. 1, Theorem 2.3), which is a generalization of the well-known Moré's existence theorem for nonlinear complementarity problems. The proof of Theorem 2.3 in Ref. 1 depends strongly on the condition 0∈K. Since this condition is rather strict for a general variational inequality, Zhao proposed an open question at the end of Ref. 1: Can the condition 0∈K in Theorem 2.3 be removed? In this paper, we answer this open question. Furthermore, we present the new notion of exceptional family of elements and establish a theorem of the alternative, by which we develop two new existence theorems for variational inequalities. Our results generalize the Zhao existence result.  相似文献   

3.
利用经验贝叶斯方法研究了刻度指数族的两行动问题, 提出了一个在历史样本被随机右删失的条件下收敛速度可以任意接近$O(n^{-1})$的单调经验贝叶斯检验.  相似文献   

4.
In this paper, we study the normality of the family of meromorphic functions from the viewpoint of hyperbolic metric. Then, a new sufficient and necessary condition is obtained, which can determine a given family of meromorphic functions is normal or not.  相似文献   

5.
本文应用陈怀惠和顾永兴关于Zalcman不正规性条件的改进结果,推广和加强了Lappan的一个正规定则.Lappan证明:若亚纯函数族中的所有函数的球面导数的幂方(大于2)在紧集上的积分一致有界,则该族是正则的.本文证明,把积分限制在函数值的模小于给定常数的子集上,结论仍然成立.同时,用高阶导数的积分替代球面导数的积分,得到十分一般的结果.另外对幂方为2的情形也进行了讨论.  相似文献   

6.
The notion of a nice local-global field, introduced and studied in the author's previous articles, is extended to the fields for which the family of all quasiclassical valuation rings is near Boolean. The main result of the article is the theorem of decidability of the elementary theory of the class of all such fields satisfying the maximality condition.  相似文献   

7.
By using the Nevanlinna theory, we prove some normality criteria for a family of meromorphic functions under a condition on differential polynomials generated by the members of the family.  相似文献   

8.
亚纯函数的正规族   总被引:2,自引:0,他引:2  
徐焱 《数学杂志》2001,21(4):381-386
关于正规族的Hayman猜测目前已完全证实,本文考虑把Hayman猜测中的 f′换为一般的f∧(k),得到一个更为一般的结果,由此改进和推广了陈怀惠,顾永兴、华歆厚,庞学诚与W.Schwick的相应结果。  相似文献   

9.
The necessary condition for the existence of a (ν, 3× 3,1)-splitting BIBD is ν ≡ 1 (mod 54). In this paper, we show that the necessary condition is also sufficient with one possible exception of ν = 55. As its application, we obtain a new infinite class of optimal 3-splitting authentication codes. AMS Classification: 05B05, 94A62 An erratum to this article is available at .  相似文献   

10.
The concept of a (q, k, λ, t) almost difference family (ADF) has been introduced and studied by C. Ding and J. Yin as a useful generalization of the concept of an almost difference set. In this paper, we consider, more generally, (q, K, λ, t, Q)-ADFs, where K = {k1, k2, ..., kr} is a set of positive integers and Q = (q1, q2,..., qr) is a given block-size distribution sequence. A necessary condition for the existence of a (q, K, λ, t, Q)-ADF is given, and several infinite classes of (q, K, λ, t, Q)-ADFs are constructed.  相似文献   

11.
A sufficient and necessary condition is given for the continuity of Julia sets in the space of all rational maps with degreek>1. Project supported by the National Natural Science Foundation of China (Grant No. 19871002).  相似文献   

12.
The concept of a (q, k, λ, t) almost dltterence tamlly (ADF) nas oeen introduced and studied by C. Ding and J. Yin as a useful generalization of the concept of an almost difference set. In this paper, we consider, more generally, (q, K,λ, t, Q)-ADFs, where K = {k1, k2,.…, kr} is a set of positive integers and Q = (q1,q2,... ,qr) is a given block-size distribution sequence. A necessary condition for the existence of a (q, K, λ, t, Q)-ADF is given, and several infinite classes of (q, K, A, t, Q)-ADFs are constructed.  相似文献   

13.
The convergence problem of the family of Euler-Halley methods is considered under the Lipschitz condition with the L-average, and a united convergence theory with its applications is presented.  相似文献   

14.
Abstract

This article introduces a family of distributional shapes which is flexible in the sense that it contains skewed and symmetric laws as well as heavy-tailed and light-tailed laws. The proposed family is also practically convenient because it is easy to fit to a table of quantiles from any distribution. Inversely, for each of the distributional shapes it is trivial to compute quantiles for any desired probability, and it is possible to compute the corresponding densities.  相似文献   

15.
The paper is devoted to a general variational approach for scaling the variable metric updates. A new method from the preconvex part of the Broyden family is given which minimizes not only the generalized Frobenius norm but also the condition number of the update. The computational efficiency of this method, with both preliminary and controlled scaling strategy, is demonstrated on sufficiently difficult test problems.  相似文献   

16.
集值变分不等式问题的例外簇   总被引:3,自引:0,他引:3  
范江华  赵康生 《数学学报》2007,50(1):183-188
本文首先在Banach空间中证明了零调集值映射的一个Leray-Schauder型不动点定理,然后在Hilbert空间中定义了零调集值映射的变分不等式的例外簇,利用本文给出的不动点定理给出了无界集上的变分不等式问题存在解的一个充分条件.此条件弱于许多已知的关于变分不等式问题的解的存在性条件,并由此得到Hilbert空间中几个变分不等式约解的存在性定理.  相似文献   

17.
A new condition for mappings, called condition (C), which is more general than nonexpansiveness, was recently introduced by Suzuki [T. Suzuki, Fixed point theorems and convergence theorems for some generalized nonexpansive mappings, J. Math. Anal. Appl. 340 (2008) 1088-1095]. Following the idea of Kirk and Massa Theorem in [W.A. Kirk, S. Massa, Remarks on asymptotic and Chebyshev centers, Houston J. Math. 16 (1990) 364-375], we prove a fixed point theorem for mappings with condition (C) on a Banach space such that its asymptotic center in a bounded closed and convex subset of each bounded sequence is nonempty and compact. This covers a result obtained by Suzuki [T. Suzuki, Fixed point theorems and convergence theorems for some generalized nonexpansive mappings, J. Math. Anal. Appl. 340 (2008) 1088-1095]. We also present fixed point theorems for this class of mappings defined on weakly compact convex subsets of Banach spaces satisfying property (D). Consequently, we extend the results in [T. Suzuki, Fixed point theorems and convergence theorems for some generalized nonexpansive mappings, J. Math. Anal. Appl. 340 (2008) 1088-1095] to many other Banach spaces.  相似文献   

18.
The convergence problem of the family of Euler-Halley methods is considered under the Lipschitz condition with the L-average,and a united convergence theory with its applications is presented.  相似文献   

19.
We prove two normality criteria for a family of meromorphic functions satisfying a certain differential condition and provide a counterexample to the converse of the Bloch principle.  相似文献   

20.
Using the topological degree and the concept of exceptional family of elements for a continuous function, we prove a very general existence theorem for the nonlinear complementarity problem. This result is an alternative theorem. A generalization of Karamardian's condition and the asymptotic monotonicity are also introduced. Several applications of the main results are presented.  相似文献   

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