How roadway composition matters in analyzing police data on racial profiling

This article argues that roadway composition data is essential to the analysis of police behavior when studying racial profiling of motorists. Police data alone show only the number and proportion of stops of African American and White drivers. They do not show how these numbers relate to the number of African American and White drivers using the roads. Proxy measures, drawn from the number of African American residents or license holders, assume that all roads in the community contain the same proportion The authors acknowledge the generous assistance of the anonymous police department that provided access. The Roadway Observation Study was supported by the Oakland University research committee and Vice-Provost Randy Hanson. We thank our research assistant

Modified Joint Weibull approach to determine Load Enhancement Factors

Load Enhancement Factor (LEF) and similar statistical methods have been used for decades to reduce the time and cost associated with component-level fatigue testing on aerospace structures. The most common LEF approach was that developed by the Naval Air Development Corporation in the 1980s. Though considered an innovative and novel concept at its conception, this traditional method has a number of limitations that restrict its applicability to only a handful of testing scenarios. The objective of this study was to deal with those restrictions and offer a more comprehensive approach to account for modern advances in statistics, composite materials, and testing technology. The formulation of the new method uses the traditional LEF method as a foundation, but uses a revised set of notation and incorporates a modified Joint Weibull analysis technique to improve its potency. A detailed set of sample calculations using stochastically generated data illustrates how the computations are performed, thus allowing practitioners to reproduce the method using their own data. A short discussion also addresses some common misconceptions regarding the use of Load Enhancement Factors