An Introduction to Statistical Issues and Methods in Metrology for Physical Science and Engineering

This article provides an overview of the interplay between statistics and measurement. Measurement quality affects inference from data collected and analyzed using statistical methods while appropriate data analysis quantifies the quality of measurements. This article brings material on statistics and measurement together in one place as a resource for practitioners. Both frequentist and Bayesian methods are discussed

Using GWAS top hits to inform priors in Bayesian fine-mapping association studies

The default causal single‐nucleotide polymorphism (SNP) effect size prior in Bayesian fine‐mapping studies is usually the Normal distribution. This choice is often based on computational convenience, rather than evidence that it is the most suitable prior distribution. The choice of prior is important because previous studies have shown considerable sensitivity of causal SNP Bayes factors to the form of the prior. In some well‐studied diseases there are now considerable numbers of genome‐wide association study (GWAS) top hits along with estimates of the number of yet‐to‐be‐discovered causal SNPs. We show how the effect sizes of the top hits and estimates of the number of yet‐to‐be‐discovered causal SNPs can be used to choose between the Laplace and Normal priors, to estimate the prior parameters and to quantify the uncertainty in this estimation. The methodology can readily be applied to other priors. We show that the top hits available from breast cancer GWAS provide overwhelming support for the Laplace over the Normal prior, which has important consequences for variant prioritisation. This work in this paper enables practitioners to derive more objective priors than are currently being used and could lead to prioritisation of different variants

Using Deficit Functions for Crew Planning in Aviation

We use deficit functions (DFs) to decompose an aviation schedule of aircraft flights into a minimal number of periodic and balanced chains (flight sequences). Each chain visits periodically a set S of airports and is served by several cockpit crews circulating along the airports of this set. We introduce the notion of ”chunks” which are a sequence of flights serviced by a crew in one day according to contract regulations. These chunks are then used to provide crew schedules and rosters. The method provides a simplicity for the construction of aircraft schedules and crew pairings which is absent in other approaches to the problem