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.
OSB is now used for about 70 percent of all floor, wall and roof sheathing in North America. Building codes, the Engineered Wood Association, architects and most builders rate plywood and oriented strand board (OSB) equal in strength and durability.SB is now used for about 70 percent of all floor, wall and roof sheathing in North America. Building codes, the Engineered Wood Association, architects and most builders rate plywood and oriented strand board (OSB) equal in strength and durability.