有期权条件下的易逝品订购策略研究

在现实生活中,有大量的易逝品存在.由于易逝品价值递减的特性和需求的不确定性,使易逝品的订购较为困难并可能在期末由于未能出售导致零售商蒙受巨大的损失.作者将期权引入了易逝品订购之中,以最大化期望收益为目标,给出了易逝品最优订购数量.     

关于分布函数的散布函数

研究了一种散布函数Ｄｘ（ｔ）的性质，得到了如下结论：设Ｘ～Ｎ（μ１，σ１２），Ｙ～Ｎ（μ２，σ２２），则Ｙ≤ＤＸσ２≤σ     

Testing for Stochastic Dominance Efficiency

We consider consistent tests for stochastic dominance efficiency at any order of a given portfolio with respect to all possible portfolios constructed from a set of assets. We justify block bootstrap approaches to achieve valid inference in a time series setting. The test statistics are computed using linear and mixed integer programming formulations. Monte Carlo results show that the bootstrap procedure performs well in finite samples. The empirical application reveals that the Fama and French market portfolio is first and second-order stochastic dominance efficient, although it is mean–variance inefficient.     

A further note on a theorem on the difference of the generalized inverses of two nonnegative definite matrices

Andrews and Phillips (1986) gave a simplified proof for the result that established the nonnegative definiteness of the difference of the Moore-Penrose inverses of two nonoegative definite matrices, a result originally due to Milliken and Akdeniz (1977), The purpose of this paper is to offer a simple proof for a generalization of this result,     

Hierarchical Variable Selection in Polynomial Regression Models

Significance tests on coefficients of lower-order terms in polynomial regression models are affected by linear transformations. For this reason, a polynomial regression model that excludes hierarchically inferior predictors (i.e., lower-order terms) is considered to be not well formulated. Existing variable-selection algorithms do not take into account the hierarchy of predictors and often select as “best” a model that is not hierarchically well formulated. This article proposes a theory of the hierarchical ordering of the predictors of an arbitrary polynomial regression model in m variables, where m is any arbitrary positive integer. Ways of modifying existing algorithms to restrict their search to well-formulated models are suggested. An algorithm that generates all possible well-formulated models is presented.     

Kurtosis and spread

An increase in kurtosis is achieved through the location- and scale-free movement of probability mass from the “shoulders” of a distribution into its centre and tails. We introduce a coherent structure of ordering and measures, requiring no symmetry assumption, that represent different formalizations of this movement. For this purpose spread functions and spread-spread plots are defined. The orderings impose growth patterns on the spread-spread plot of the distributions involved, and the weakest involve both a specific scale-matching technique and placement of “shoulders”. The role of existing kurtosis orderings and measures in this general context is identified and examples discussed throughout.     

震后交通管制下多出救点应急物资调运问题

销售季节性商品的零售企业在销售季节开始前通常仅能获得有限的市场信息,在销售过程中因滞销而产生剩余库存的现象十分普遍。因此,许多零售企业会将商品在一级市场销售之后以折扣价格在二级市场上继续销售。为此,建立了这一问题的两阶段模型,在较宽松的需求假设下分析了模型所具有的性质,通过求解得到了零售企业对季节性商品的订货量决策和商品在两级市场间转换时刻决策所要满足的最优条件。     

论社区零售订购业态

在短缺经济时代甚至直到19世纪,零售订购依然是人类重要的购物方式和销售方式。大工业资本主义的兴起几乎摧毁了零售订购业。在经济高速发展的今天,社区零售订购又恢复了他的生机,电话和电视订购也赋予了它新的涵义。B2C零售订购业将成为中国电子商务的E—SHOP零售营销大趋势。     

Concepts and measures for skewness with data-analytic implications

The decomposition of the distribution function into skewness and spread functions serves as a basis for conceptualizing the skewness of a random variable. Measures of skewness are also described in terms of the skewness and spread functions, thereby unifying the measures with the concepts. Results that relate these measures to whether one random variable is more skewed than another are reviewed and extended. Graphical displays are presented for uncovering the nature of the skewness of a variable. The measures are also linked to the issue of symmetrizing a variable.     

选择价值工程改进对象的动态排序模型

从一个复杂系统中,合理地选择重点改进对象,是有效开展价值工程活动的基础。本文在分析最合适区域法存在的问题的基础上,提出选择价值工程改进对象的动态排序模型。