利用F-O模型对中国物流上市公司内在价值的评价

以我国沪、深两市上市的物流企业为对象,研究目前西方最为前沿的价值模型(F-O模型)的基本指标对我国物流企业价值评价的解释能力,并对其内在价值以及价值偏离度进行模拟测算及分析。     

On the performance of the minimum VaR portfolio

Alexander and Baptista [2002. Economic implications of using a mean-value-at-risk (VaR) model for portfolio selection: A comparison with mean–variance analysis. Journal of Economic Dynamics and Control 26: 1159–93] develop the concept of mean-VaR efficiency for portfolios and demonstrate its very close connection with mean–variance efficiency. In particular, they identify the minimum VaR portfolio as a special type of mean–variance efficient portfolio. Our empirical analysis finds that, for commonly used VaR breach probabilities, minimum VaR portfolios yield ex post returns that conform well with the specified VaR breach probabilities and with return/risk expectations. These results provide a considerable extension of evidence supporting the empirical validity and tractability of the mean-VaR efficiency concept.     

Exact relations between Luenberger productivity indicators and Malmquist productivity indexes

In this note we derive an exact relation between Luenberger productivity indicators and Malmquist productivity indexes. The authors are grateful for referee comments which substantially improved the paper.     

基于旋转电弧传感器的TIG焊焊枪偏差信息识别研究

为减轻外界噪声对焊接电压信号的干扰,本文在采用中值滤波方法、均值滤波方法的基础上将旋转电弧传感器采集到的电压信号进行过滤,使得电压波形得到明显的改善。为了准确获取信息,本文采用左右积分方法和焊枪偏差识别算法检测偏差,并将结果进行对比,从而获得更好的焊枪偏差信息。     

双侧限“σ”法抽样方案的设计（均值）——关于GB／T8054—2008表2的设计建议

文章利用文献[1]中的理论公式和数据表，给出了以均值为质量指标的双侧限“σ”法抽样方案表。该抽样方案表的设计是对GB／T8054—2008表2的改进，不仅符合设计目标，而且更便于应用。     

3DCS三维偏差分析软件分析汽车柔性零件的应用

文章以上汽通用五菱汽车股份有限公司(SGMW)新车型的研发为载体,对应用三维偏差分析软件3DCS分析汽车柔性零件原理及其方法进行探讨,结合有限元方法与3DCS软件的对比,总结应用3DCS软件分析柔性零件的技巧和方法。     

Sampling with probabilities proportional to the variable of interest

To estimate the mean sojourn time, a sample of Tilburg fair visitors was asked for the duration of their stay on the fair grounds. The longer a visitor's sojourn, the larger his/her probability of being interviewed will be; therefore, longer sojourn times will be overrepresented in the sample. As a consequence, the arithmetic sample mean is not a good estimator.
The paper places this problem against a theoretical background. Sampling with unequal probabilities is considered in a general context. The special case that the sampling probabilities are a function of the variable under investigation, is discussed in detail. As a better estimator the harmonic mean of the observations is presented. Most properties of this estimator are difficult to derive analytically, but a suitable variance estimator is derived. The behavior of estimator and variance estimator is studied in a number of quite different examples.     

A NOTE ON THE TRIMMED MEAN MEASURE OF CORE INFLATION IN SOUTH AFRICA

This paper constructs and analyses the properties of a trimmed mean inflation rate for South Africa. Based on an analysis of the distributions of the consumer price index component price changes, a measure is constructed that provides an estimator of core inflation, which may be particularly useful to policymakers in an inflation‐targeting environment. The trimmed mean estimator focuses on the price movements of individual components that have a strong bearing on the current and future trend of the headline inflation rate, allowing monetary policy to be directed at the persistent or underlying sources of inflationary pressures.     

不查表即能确定质量水平的公式

系统地阐述了Zsσ控制方式的概念，探讨了控制方式与缺陷率的数量关系，在研究过程能力指数算例中，偶然发现了不用查表即能确定质量水平的公式。     

The risk‐return paradox for strategic management: disentangling true and spurious effects

The concept of risk is central to strategy research and practice. Yet, the expected positive association between risk and return, familiar from financial markets, is elusive. Measuring risk as the variance of a series of accounting‐based returns, Bowman obtained the puzzling result of a negative association between risk and mean return. This finding, known as the Bowman paradox, has spawned a remarkable number of publications, and various explanations have been suggested. The present study contributes to this literature by showing that skewness of individual firm' return distributions has a considerable spurious effect on the empirically estimated mean‐variance relationship. I devise a method to disentangle true and spurious effects, illustrate it using simulations, and apply it to empirical data. It turns out that the size of the spurious effect is such that, on average, it explains the larger part of the observed negative relationship. My results might thus help to reconcile mean‐variance approaches to risk‐return analysis with other, ex‐ante, approaches. In concluding, I show that the analysis of skewness is linked to all three streams of literature devoted to explaining the Bowman paradox. Copyright © 2008 John Wiley & Sons, Ltd.