turbine: Turbine wheel crack initiation data

In Auburngrads/SMRD: Statistical Methods For Reliability Data

Description

Nelson (1982) describes a study to estimate the distribution of time to crack initiation for turbine wheels. Each of 432 wheels were inspected once to determine if it had started to crack or not. At the time of the inspections, the wheels had different amounts of service time (age). A unit found to be cracked at its inspection was labelled as left-censored at its age (because the crack had initiated at some unknown point before its inspection age). A unit found to be uncracked at its inspection was labelled as right-censored at its age (because a crack would be initiated at some unknown point after that age). The data show the number of cracked and uncracked wheels in different age categories, showing the midpoint of the time interval given by Nelson. The data were put into intervals to facilitate simpler analyses.

Format

A data.frame with 21 rows and 3 variables:

[, 1]	hours	Accumulated hours (in hundreds) at event	Numeric
[, 2]	event	Event observed at hours (right-censored/left-censored)	Categoric
[, 3]	count	Number of events observed at hours	Numeric

Source

Nelson, W. (1982) Applied Life Data Analysis, New York, NY: John Wiley \& Sons.

Auburngrads/SMRD documentation built on Sept. 14, 2020, 2:21 a.m.