Donald Tepas

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Data obtained from surveys of two samples of maritime crew members were studied for differences in self-reported sleep lengths and sleep problems. The data addressed both on- and off-duty variables. Statistical analysis of the data found that on-duty sleep length was shorter than off-duty sleep length for both groups. The two groups' responses to various(More)
The study describes an investigation of the relationship between crash occurrence and hourly volume counts for small samples of highway segments from two states: Michigan and Connecticut. We used a hierarchical Bayesian framework to fit binary regression models for predicting crash occurrence for each of four crash types: (1) single-vehicle, (2)(More)
Fatigue has often been viewed as a simple variable that is positively correlated with time on task in the workplace and is produced mainly by physical activity. However, shiftwork researchers have demonstrated time-of-day differences for variables including sleepiness and mood, thereby challenging this notion of fatigue. Using a within-subjects design, the(More)
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