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We give a construction for regular Hadamard matrices of order $a^{2} v$ where $a \neq 1$ is the order of a Hadamard matrix and $v$ is the order of a regular Hadamard matrix. The construction can be used to construct regular Hadamard matrices with special properties and includes several constructions which have been given previously. In the final section we consider the case $a = 2$ in more detail.

On cardinalities of row spaces of Boolean matrices.

J. Konieczny (1992)

Semigroup forum

On Difference Matrices, Resolvable Transversal Designs and Generalized Hadamard Matrices.

Dieter Jungnickel (1979)

Mathematische Zeitschrift

On idempotent binary relations on a finite set

Štefan Schwarz (1970)

Czechoslovak Mathematical Journal

On large random almost euclidean bases.

Vershynin, R. (2000)

Acta Mathematica Universitatis Comenianae. New Series

On powers of non-negative matrices

Antonín Vrba (1973)

Časopis pro pěstování matematiky

On special structure of graphs having the maximal eigenvalue greater than two.

D.M. Cvetkovic, I. Gutman (1974)

Publications de l'Institut Mathématique [Elektronische Ressource]

On Spectral Structure Of Graphs Having The Maximal Eigenvalue Not Grater Than Two

D. M. Cvetković, I. Gutman (1975)

Publications de l'Institut Mathématique

On Supplementary Difference Sets.

Jennifer Wallis (1972)

Aequationes mathematicae

On the combinatorial structure of $0 / 1$ -matrices representing nonobtuse simplices

Jan Brandts, Abdullah Cihangir (2019)

Applications of Mathematics

A $0 / 1$ -simplex is the convex hull of $n + 1$ affinely independent vertices of the unit $n$ -cube $I^{n}$ . It is nonobtuse if none of its dihedral angles is obtuse, and acute if additionally none of them is right. Acute $0 / 1$ -simplices in $I^{n}$ can be represented by $0 / 1$ -matrices $P$ of size $n \times n$ whose Gramians $G = P^{⊤} P$ have an inverse that is strictly diagonally dominant, with negative off-diagonal entries. In this paper, we will prove that the positive part $D$ of the transposed inverse $P^{- ⊤}$ of $P$ is doubly stochastic and has the same support...

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O Hadamardově determinantu

O počtu tříd silně ekvivalentních incidenčních matic

On a combinatorical problem of K. Zarankiewicz

On a conjecture of the semigroup of fully indecomposable relations

On a construction of regular Hadamard matrices

On cardinalities of row spaces of Boolean matrices.

On Difference Matrices, Resolvable Transversal Designs and Generalized Hadamard Matrices.

On idempotent binary relations on a finite set

On large random almost euclidean bases.

On powers of non-negative matrices

On special structure of graphs having the maximal eigenvalue greater than two.

On Spectral Structure Of Graphs Having The Maximal Eigenvalue Not Grater Than Two

On Supplementary Difference Sets.

On the combinatorial structure of $0 / 1$ -matrices representing nonobtuse simplices

On the Construction and Characterisation of a Class of Designs.

On the existence of (196,91,42) Hadamard difference sets

On the exponent of $r$ -regular primitive matrices.

On the number of possible row and column sums of $0, 1$ -matrices.

On the semigroup of binary relations on a finite set

On the twin designs with the Ionin-type parameters.

Currently displaying 1 – 20 of 23