A sparse ruler is called optimal if it is both minimal and maximal. Since the number of distinct pairs of marks is m ( m â 1 ) / 2 {\displaystyle m(m-1)/2} , this is an upper bound on the length L {\displaystyle L} of any maximal sparse ruler with m {\displaystyle m} marks.
1 One 23/32-inch 4x8-foot plywood piece weighs approximately 67 pounds, while a piece of OSB of the same dimensions weighs approximately 78 pounds.
Plywood long ago lost its market leadership to oriented strand board (OSB), which is now the most-used sheathing and subflooring material. Estimates put its market share as high as 75%, with much of that dominance thanks to cost-conscious production builders.n the downside, the material is a bit heavier than plywoodâtwo pounds or more per sheet depending on its thickness and intended useâbut this difference has no effect on the panelsâ performance. It just takes a bit more muscle to handle on the jobsite.