2 citations · 7 across the 28 of their papers we have counts for
30 papers
Unbiased weighing matrices of weight
Makoto Araya, Masaaki Harada, Hadi Kharaghani +2
We investigate unbiased weighing matrices of weight and provide a construction method using mutually suitable Latin squares. For , we determine the maximum size among…
Constructions of self-orthogonal and LCD subspace codes
Dean Crnković, Keita Ishizuka, Hadi Kharaghani +2
Recently, the notions of self-orthogonal subspace codes and LCD subspace codes were introduced, and LCD subspace codes obtained from mutually unbiased weighing matrices were studie…
On the classification of skew Hadamard matrices of order 36 and related structures
Makoto Araya, Masaaki Harada, Hadi Kharaghani +2
Two skew Hadamard matrices are considered {\sf SH}-equivalent if they are similar by a signed permutation matrix. This paper determines the number of {\sf SH}-inequivalent skew Had…
Embeddable partial Hadamard matrices related to the projective planes
Hadi Kharaghani, Sho Suda, Yash Shamsundar Khobragade
The existence of a projective plane of order , where is a prime power, is shown to be equivalent to the existence of a balancedly multi-splittable embeddable…
On optimal constant weight codes derived from -circulant balanced generalized weighing matrices
Hadi Kharaghani, Thomas Pender, Vladimir D. Tonchev
A family of -circulant balanced weighing matrices with classical parameters is used for the construction of optimal constant weight codes over an alphabet of size and leng…
Ternary extremal four-negacirculant self-dual codes
Masaaki Harada, Keita Ishizuka, Hadi Kharaghani
In this note, we give basic properties of ternary four-negacirculant self-dual codes. By exhaustive computer search based on the properties, we complete a classification of ternary…
Hadamard matrices related to the projective planes
Hadi Kharaghani, Sho Suda
Let be the order of a (quaternary) Hadamard matrix. It is shown that the existence of a projective plane of order is equivalent to the existence of a balancedly multi-split…
Quasi-balanced weighing matrices, signed strongly regular graphs and association schemes
Hadi Kharaghani, Thomas Pender, Sho Suda
A weighing matrix is quasi-balanced if has at most two off-diagonal entries, where . A quasi-balanced weighing matrix signs a s…
Balanced Weighing Matrices
Hadi Kharaghani, Thomas Pender, Sho Suda
A unified approach to the construction of weighing matrices and certain symmetric designs is presented. Assuming the weight in a weighing matrix is a prime power, it i…
On a class of optimal constant weight ternary codes
Hadi Kharaghani, Sho Suda, Vlad Zaitsev
A weighing matrix of order and weight is constructed and shown that the rows of and form optimal constant weight ternary codes of lengt…
A family of balanced generalized weighing matrices
Hadi Kharaghani, Thomas Pender, Sho Suda
Balanced weighing matrices with parameters for each nonzero integer is constructed. This is the first infini…
Balancedly splittable orthogonal designs and equiangular tight frames
Hadi Kharaghani, Thomas Pender, Sho Suda
The concept of balancedly splittable orthogonal designs is introduced along with a recursive construction. As an application, equiangular tight frames over the real, complex, and q…
Divisible design digraphs and association schemes
Hadi Kharaghani, Sho Suda
Divisible design digraphs are constructed from skew balanced generalized weighing matrices and generalized Hadamard matrices. Commutative and non-commutative association schemes ar…
Disjoint weighing matrices
Hadi Kharaghani, Sho Suda, Behruz Tayfeh-Rezaie
The notion of disjoint weighing matrices is introduced as a generalization of orthogonal designs. A recursive construction along with a computer search lead to some infinite classe…
New constructions of Deza digraphs
Dean Crnkovic, Hadi Kharaghani, Sho Suda +1
Deza digraphs were introduced in 2003 by Zhang and Wang as directed graph version of Deza graphs, that also generalize the notion of directed strongly regular graphs. In this paper…
Divisible design Cayley digraphs
Dean Crnkovic, Hadi Kharaghani, Andrea Svob
Divisible design digraphs which can be obtained as Cayley digraphs are studied. A characterization of divisible design Cayley digraphs in terms of the generating sets is given. Fur…
Balancedly splittable Hadamard matrices
Hadi Kharaghani, Sho Suda
Balancedly splittable Hadamard matrices are introduced and studied. A connection is made to the Hadamard diagonalizable strongly regular graphs, maximal equiangular lines set, and…
Linked systems of symmetric group divisible designs of type II
Hadi Kharaghani, Sho Suda
The linked systems of symmetric group divisible designs of type II is introduced, and several examples are obtained from affine resolvable designs and mutually UFS Latin squares. F…
On a class of quaternary complex Hadamard matrices
Kai Fender, Hadi Kharaghani, Sho Suda
We introduce a class of regular unit Hadamard matrices whose entries consist of two complex numbers and their conjugates for a total of four complex numbers. We then show that thes…
Commutative association schemes obtained from twin prime powers, Fermat primes, Mersenne primes
Hadi Kharaghani, Sho Suda
For prime powers and where , an affine resolvable design from and Latin squares from yield a…
Non-commutative association schemes and their fusion association schemes
Hadi Kharaghani, Sho Suda
We give a sufficient condition for a non-commutative association scheme to have a fusion association scheme, and construct non-commutative association schemes from symmetric balanc…
Strongly regular decompositions and symmetric association schemes of a power of two
Hadi Kharaghani, Sara Sasani, Sho Suda
For any positive integer , the complete graph on vertices is decomposed into commuting strongly regular graphs, which give rise to a symmetric associatio…
Linked systems of symmetric group divisible designs
Hadi Kharaghani, Sho Suda
We introduce the concept of linked systems of symmetric group divisible designs. The connection with association schemes is established, and as a consequence we obtain an upper bou…
Unbiased orthogonal designs
Hadi Kharaghani, Sho Suda
The notion of unbiased orthogonal designs is introduced as a generalization among unbiased Hadamard matrices, unbiased weighing matrices and quasi-unbiased weighing matrices. We pr…