Recent and classical tests for exponentiality: a partial review with comparisons

A wide selection of classical and recent tests for exponentiality are discussed and compared. The classical procedures include the statistics of Kolmogorov-Smirnov and Cramér-von Mises, a statistic based on spacings, and a method involving the score function. Among the most recent approaches emphasized are methods based on the empirical Laplace transform and the empirical characteristic function, a method based on entropy as well as tests of the Kolmogorov-Smirnov and Cramér-von Mises type that utilize a characterization of exponentiality via the mean residual life function. We also propose a new goodness-of-fit test utilizing a novel characterization of the exponential distribution through its characteristic function. The finite-sample performance of the tests is investigated in an extensive simulation study.Received: January 2002/Revised: January 2004     

成为优秀维修的方法

大部分企业都力图获得最大的利润率。这是所有工业企业普遍遇到的问题。要成功地完成这项任务，维修部门也必须实施适当的管理方法。任何一个企业在进行这项工作时，假如目标是成为优秀维修，就需要有一个逐步渐进的维修改革，这与是否拥有先进技术无关。     

Die Entwicklung der HSH Nordbank als Landesbank — einige Einschätzungen

Some of the German “Landesbanken” engaged in highly risky business with the acceptance of local politicians and then demanded bailouts during the financial crisis. The HSH Nordbank, the world’s largest provider of ship financing, based in northern Germany, lost almost 2.8 billion euros in 2008. The two German shareholders, the states of Hamburg and Schleswig-Holstein, had to agree on a 13 billion euro bailout plan for the bank (3 billion euros in cash and a “risk shield” of 10 billion euros). Furthermore, the German government provided the HSH Nordbank with 17 billion euros of liquidity guarantees under the Special Financial Market Stabilisation Fund (SOFFIN). In view of this situation, the following questions should be answered: What role did the merger of the Hamburger Landesbank and Landesbank Schleswig-Holstein play in the development of the HSH Nordbank? Was there a possibility to merge the HSH Nordbank with another bank to avoid the financial difficulties? Were the extensive conditions set by the EU Commission in the state aid proceedings too restrictive? What are the actual costs of the HSH Nordbank’s bailout programme for the shareholders and their governmental budgets?     

Kurz Kommentiert

KURZ KOMMENTIERT

Kurz Kommentiert     

Group-based forecasting?: A social psychological analysis

The potential of group (vs. individual) forecasting is analyzed from the perspective of the social psychology of groups. The social decision scheme theory (SDST) is summarized, and several simulations are presented to demonstrate the dependence of group aggregation accuracy upon factors such as group size, the accuracy and distribution of individual forecasts, and shared representations of the forecasting problem. Many advantages and disadvantages of group aggregation are identified and related to four generic methods of group aggregation (statistical aggregation, prediction markets, the Delphi method, and face-to-face discussion). A number of aspects of forecasting problems are identified which should govern whether or not group forecasting can be relied upon, and if so, what aggregation method should be used.