A complete asymptotic expansion of power means

The complete asymptotic expansion of power means in terms of Bell polynomials is obtained. Some results recently obtained by M. Bjelica are generalized.     

上海股市波动的预测方式和模型

探讨基于 SV类模型的上海股市波动的预测方式和模型问题 .比较了 SV( stochastic volatility)类模型 (包括基本 SV模型和 ASV模型 )在两种不同方式下的预测效果 ,并将基本 SV类模型的预测效果与 ASV模型 ,以及其他常用模型做了比较 .结果表明 :SV类模型在两种预测方式下的预测效果存在一定的差异 ;基本 SV模型对于上海股市具有较强的预测能力 ;ASV模型的预测效果不理想 .     

茶叶中汞的测定

应用程序控温－湿法消解－氢化物发生－冷原子吸收光谱法对茶叶中的汞进行了消解、测定，对可能影响测定的相关因素进行了研究和探讨。回收率为95．0％－104．5％，相对标准偏差为3．8％。与国家标准方法对照，无显著差异。     

Generalized Deviations and Best Approximation Theory

ABSTRACT

Given the importance of standard deviation in applications, we think that it is worthwhile considering other types of deviations. For this purpose, we introduce a generalization of the concept of deviation. We also introduce a new definition for the concept of generalized mean. We then highlight the connection that exists between arithmetic mean, standard deviation, and best approximation, and we establish necessary and sufficient conditions that would guarantee the existence of similar connections between generalized means, generalized deviations, and best approximation. We finish by presenting some open problems.     

The Mean-Partition Problem

In mean-partition problems the goal is to partition a finite set of elements, each associated with a d-vector, into p disjoint parts so as to optimize an objective, which depends on the averages of the vectors that are assigned to each of the parts. Each partition is then associated with a d × p matrix whose columns are the corresponding averages and a useful approach in studying the problem is to explore the mean-partition polytope, defined as the convex hull of the set of matrices associated with feasible partitions.     

几何—算术平均不等式的变种

<正> 几何—算术平均不等式,在数学的许多分支中(见文[1][2]及[3])都有广泛的应用。本文中将给出几何—算术平均不等式的两个有用的变形。首先来引入一些记号。假定     

基于样本最大分类信息的聚类有效性函数

根据每一样本的最大分类信息，对Bezdek定义的划分系数进行修改，提出了一个新的聚类有效性函数，讨论了该函数的若干性质。实验结果表明在某些情形该函数的判决效果优于划分系数。     

Inequalities and bounds for elliptic integrals

Computable lower and upper bounds for the symmetric elliptic integrals and for Legendre's incomplete integral of the first kind are obtained. New bounds are sharper than those known earlier. Several inequalities involving integrals under discussion are derived.     

单位球面上Hardy空间中Cesaro平均的逼近及几乎处处收敛问题

利用球面上Cesaro平均的性质，通过对各种乘子的估计，讨论了单位球面上Hardy空间H^p（Ωn）（0＜p≤1）中Cesaro平均在临界指标和高于临界指标的有界性和逼近，并且研究了Cesaro平均的几乎处处收敛问题。     

On the Hyers-Ulam Stability Problem for Quadratic Multi-dimensional Mappings on the Gaussian Plane

In this paper we solve the Hyers-Ulam stability problem for quadratic multidimensional mappings on the Gaussian plane.AMS Subject Classification (1991): 39B