Symmetry and order in the portfolio allocation problem

Summary. This research studies the role of multivariate distribution structures on random asset returns in determining the optimal allocation vector for an expected utility maximizer. All our conclusions pertain for the set of risk averters. By carefully disturbing symmetry in the distribution of the, possibly covarying, returns, we ascertain the ordinal structure of the optimized allocation vector. Rank order of allocations is also established when a permutation symmetric random vector is mapped into the returns vector through location and scale shifts. It is shown that increased dispersion in the vectors of location and scale parameters benefit, ex-ante, investors as does a decrease in the rank correlation coefficient between the location and scale parameter vectors. Revealed preference comparative static results are identified for the location and scale vectors of asset returns. For most issues addressed, we arrive at much stronger inferences when a safe asset is available. Received: August 8, 2000; revised version: January 8, 2001     

电子商务的风险管理与审计研究

电子商务尽管现在处于低潮期，但是作为重要的变革力量，它仍然是2l世纪的一个必然趋势。另外，电子商务发展受阻的一个重要原因就是电子商务的安全问题，这一问题影响了消费的决策，也极大地改变了企业的整个风险结构。本从外部审计与内部审计两个角度分析了审计可以在应对电子商务风险中发挥的重要作用。从外部审计来看，数据完整性与机密性是网站审计与认证的重要方面，从内部审计来看，审计应该在包括了电子商务风险的全面风险管理框架内发挥重要的作用。     

Asymmetric performance: the market share impact of scale and link alliances in the global auto industry

This study investigates how participating in strategic alliances with rivals affects the relative competitive positions of the partner firms. The paper builds on studies that show significant differences in the outcomes of scale and link alliances. The study argues that the more asymmetric outcomes of link alliances translate into greater changes in the relative market shares of the partner firms, due to unbalanced opportunities for inter‐partner learning and learning by doing. We find support for this argument by examining 135 alliances among competing firms in the global automobile industry, from 1966 to 1995. Copyright © 2004 John Wiley & Sons, Ltd.     

中小企业成长的理论

概根据相关文献资料对中小企业成长的理论观点,本文作了归纳、整理,目的在于识别影响和决定其成长的关键因素,理解和把握其生存发展的规律,以有助于从事创业的企业家和中小企业经营管理者借鉴,为政府制订面向中小企业的支持体系建设提供理论依据。     

土工实验中的液、塑限测定浅议

文章分析了当前土工实验中的液、塑限测定过程中应当注意的问题及其存在的问题,并论述了如何对其实验数据进行处理和分析的方法。     

A Pricing and Hedging Comparison of Parametric and Nonparametric Approaches for American Index Options

This article investigates the extent to which options on theAustralian Stock Price Index can be explained by parametricand nonparametric option pricing techniques. In particular,comparisons are made of out-of-sample option pricing performanceand hedging performance. The dataset differs from many of thoseused previously in the empirical options pricing literaturein that it consists of American options. In addition, a broaderspectrum of techniques are considered: a spline-based nonparametrictechnique is considered in addition to the standard kernel techniques,while the performance of a Heston stochastic volatility modelis also considered. Although some evidence is found of superiorperformance by nonparametric techniques for in-sample pricing,the parametric methods exhibit a markedly better ability toexplain future prices and show superior hedging performance.     

仓库物资装卸最优性方案的选择

军队后方仓库是军用物资装备的储备基地，是军队物流系统的一个重要环节。如何利用现有条件，提高日常乃至战时仓库的收发、存储能力和工作效率，是提高军队后勤保障能力的一个重要课题。本文对仓库物资装卸中的几个主要技术经济指标进行探讨分析。     

自适应调制与编码系统及其在WCDMA中的应用

本文主要讨论自适应调制与编码系统(Adaptive Modulation and Coding system）的原理，介绍AMCS实现的几个关键技术，包括RCPT（速率适配凿孔turbo）码、高阶调制、H-ARQ和MIMO（多输入多输出）系统。介绍了在WCDMA的高速下行分组接入业务（HSDPA）中使用的自适应调制编码机制，并讨论了可能增加的设备复杂度。     

Stock Price and Volume Effects Associated with Compositional Changes in European Stock Indices

This paper provides further evidence of price and volume effects associated with index compositional changes by analysing the inclusions (exclusions) from the French CAC40 and SBF120 indices, as well as the FTSE100. I find evidence supporting the price pressure hypothesis associated with index fund rebalancing, but weak or no evidence for the imperfect substitution, liquidity and information hypotheses. The results improve on recent evidence from the S&P500 index. The evidence for the FTSE100 additions shows, in particular, that markets learn about an imminent inclusion and incorporate this information into prices, even before the announcement date.