scholarly journals A Construction Method for Complete Sets of Mutually Orthogonal Frequency Squares

10.37236/1543 ◽  
2000 ◽  
Vol 7 (1) ◽  
Author(s):  
V C Mavron

A construction is described for combining affine designs with complete sets of mutually orthogonal frequency squares to produce other complete sets.

10.37236/1534 ◽  
2000 ◽  
Vol 7 (1) ◽  
Author(s):  
V C Mavron

The known methods for constructing complete sets of mutually orthogonal frequency squares all yield one of two parameter sets. We show that almost all these constructions can be derived from one basic design theory construction.


10.37236/9373 ◽  
2020 ◽  
Vol 27 (3) ◽  
Author(s):  
Thomas Britz ◽  
Nicholas J. Cavenagh ◽  
Adam Mammoliti ◽  
Ian M. Wanless

A frequency square is a matrix in which each row and column is a permutation of the same multiset of symbols. We consider only binary frequency squares of order $n$ with $n/2$ zeros and $n/2$ ones in each row and column. Two such frequency squares are orthogonal if, when superimposed, each of the 4 possible ordered pairs of entries occurs equally often. In this context we say that a set of $k$-MOFS$(n)$ is a set of $k$ binary frequency squares of order $n$ in which each pair of squares is orthogonal. A set of $k$-MOFS$(n)$ must satisfy $k\le(n-1)^2$, and any set of MOFS achieving this bound is said to be complete. For any $n$ for which there exists a Hadamard matrix of order $n$ we show that there exists at least $2^{n^2/4-O(n\log n)}$ isomorphism classes of complete sets of MOFS$(n)$. For $2<n\equiv2\pmod4$ we show that there exists a set of $17$-MOFS$(n)$ but no complete set of MOFS$(n)$. A set of $k$-maxMOFS$(n)$ is a set of $k$-MOFS$(n)$ that is not contained in any set of $(k+1)$-MOFS$(n)$. By computer enumeration, we establish that there exists a set of $k$-maxMOFS$(6)$ if and only if $k\in\{1,17\}$ or $5\le k\le 15$. We show that up to isomorphism there is a unique $1$-maxMOFS$(n)$ if $n\equiv2\pmod4$, whereas no $1$-maxMOFS$(n)$ exists for $n\equiv0\pmod4$. We also prove that there exists a set of $5$-maxMOFS$(n)$ for each order $n\equiv 2\pmod{4}$ where $n\geq 6$.


2009 ◽  
Vol 129 (5) ◽  
pp. 715-716
Author(s):  
Shoichi Minami ◽  
Satoshi Morii ◽  
Suo Lian ◽  
Shunji Kawamoto

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