4
\title{Evaluation of Stress in Railway Rails}
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The \code{Rail} data frame has 18 rows and 2 columns.
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This data frame contains the following columns:
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an ordered factor identifying the rail on which the
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a numeric vector giving the travel time for ultrasonic
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head-waves in the rail (nanoseconds). The value given is the
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original travel time minus 36,100 nanoseconds.
23
Devore (2000, Example 10.10, p. 427) cites data from an article in
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\emph{Materials Evaluation} on ``a study of travel time for a certain
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type of wave that results from longitudinal stress of rails used for
29
Pinheiro, J. C. and Bates, D. M. (2000), \emph{Mixed-Effects Models in S
30
and S-PLUS}, Springer, New York. (Appendix A.26)
32
Devore, J. L. (2000), \emph{Probability and Statistics for
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Engineering and the Sciences (5th ed)}, Duxbury, Boston, MA.