Für die Käufer von Sammelbildern stellt sich häufig die Frage, wie viele Käufe sie tätigen müssen, um eine bestimmte Anzahl von Bildern, die zu Gruppen in Tüten verpackt sind, zu erhalten. Zur Lösung dieser und ähnlicher Fragen untersuchen wir Verallgemeinerungen des Belegungsproblems...

Many software reliability growth models assume that the time to next failure may be infinite; i.e., there is a chance that no failure will occur at all. For most software products this is too good to be true even after the testing phase. Moreover, if a non-zero probability is assigned to an...

Most software reliability growth models specify the expected number of failures experienced as a function of testing effort or calendar time. However, there are approaches to model the development of intermediate factors driving failure occurrences. This paper starts out with presenting a model...

A number of recent studies have reported the phenomenon of “software aging”, characterized by progressive performance degradation and/or an increased occurrence rate of hang/crash failures of a software system due to the exhaustion of operating system resources or the accumulation of errors....

Keynes (1911) derived general forms of probability density functions for which the "most probable value" is given by the arithmetic mean, the geometric mean, the harmonic mean, or the median. His approach was based on indirect (i.e., posterior) distributions and used a constant prior...

"This paper illustrates the effects of item-nonresponse in surveys on the results of multivariate statistical analysis when estimation of productivity is the task. To multiply impute the missing data a data augmentation algorithm based on a normal/Wishart model is applied. Data of the German IAB...

"For micro-datasets considered for release as scientific or public use files, statistical agencies have to face the dilemma of guaranteeing the confidentiality of survey respondents on the one hand and offering sufficiently detailed data on the other hand. For that reason a variety of methods to...

"In this paper, we remove one serious drawback of the IAB employment sample impeding its applicability to the estimation of earnings frontiers: the censoring of the income data, by multiple imputation. Then, we estimate individual potential income with stochastic earnings frontiers, and we...

"In order to analyze the gender wage gap with the German IAB-employment sample we have to solve the problem of censored wages at the upper limit of the social security system. We treat this problem as a missing data problem. We regard the missingness mechanism as not missing at random (NMAR,...

"Der Beitrag gibt einen Überblick über aktuelle Forschungsprojekte des Instituts für Arbeitsmarkt- und Berufsforschung (IAB), die sich alle auf unterschiedliche Weise mit der Behebung von Problemen mit Missing Data befassen. Hierzu gehören einerseits Projekte, die Stichproben verwenden wie...