Some new infinite series of Freeman-Youden rectangles

A Freeman-Youden rectangle (FYR) is a Graeco-Latin row-column design consisting of a balanced superimposition of two Youden squares. There are well known infinite series of FYRs of size q x (2q + 1) and (q + 1) x (2q + 1) where 2q + 1 is a prime power congruent to 3 (modulo 4). However, Preece and Cameron [9] additionally gave a single FYR of size 7 x 15. This isolated example is now shown to belong to one of a set of infinite series of FYRs of size q x (2q + 1) where q, but not necessarily 2q +1, is a prime power congruent to 3 (modulo 4), q > 3; there are associated series of FYRs of size (q + 1) x (2q + 1). Both the old and the new methodologies provide FYRs of sizes 9 x (2q + 1) and (q + 1) x (2q + 1) where both q and 2q + 1 are congruent to 3 (modulo 4), q > 3; we give special attention to the smallest such size, namely 11 x 23

Relations among partitions

Combinatorialists often consider a balanced incomplete-block design to consist of a set of points, a set of blocks, and an incidence relation between them which satisfies certain conditions. To a statistician, such a design is a set of experimental units with two partitions, one into blocks and the other into treatments: it is the relation between these two partitions which gives the design its properties. The most common binary relations between partitions that occur in statistics are refinement, orthogonality and balance. When there are more than two partitions, the binary relations may not suffice to give all the properties of the system. I shall survey work in this area, including designs such as double Youden rectangles.PostprintPeer reviewe