cifies the time
periods for the units of each panel to be sampled based on searching for a
D-optimal block design that is a member of the class of generalized Youden
designs.  The resulting design need not be a balanced incomplete block
design.  Based on algorithmic idea by Cook and Nachtsheim (1989) and
implemented by Robert Wheeler."><meta property="og:image" content="https://usepa.github.io/spsurvey/logo.png"><!-- mathjax --><script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js" in