On equivalence of Hadamard matrices and projection properties

Georgiou, S; Koukouvinos, C

dc.contributor.author	Georgiou, S	en
dc.contributor.author	Koukouvinos, C	en
dc.date.accessioned	2014-03-01T01:19:21Z
dc.date.available	2014-03-01T01:19:21Z
dc.date.issued	2003	en
dc.identifier.issn	0381-7032	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15440
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0242350472&partnerID=40&md5=1e200d75560e9bac1b4c7a41ff349d62	en
dc.relation.uri	http://www.informatik.uni-trier.de/~ley/db/journals/arscom/arscom69.html#GeorgiouK03	en
dc.subject	Algorithm	en
dc.subject	Equivalence	en
dc.subject	Hadamard matrices	en
dc.subject	Hamming distance	en
dc.subject	Projection	en
dc.subject	Symmetric Hamming distance	en
dc.subject.classification	Mathematics	en
dc.subject.other	CLASSIFICATION	en
dc.subject.other	ORDER-28	en
dc.subject.other	DESIGNS	en
dc.title	On equivalence of Hadamard matrices and projection properties	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2003	en
heal.abstract	The classification of Hadamard matrices of orders n greater than or equal to 32 is still remains an open and difficult problem. The definition of equivalent Hadamard matrices gets to have huge complexity as n is getting bigger. One efficient criterion (K-boxes) used for the construction of inequivalent Hadamard matrices in order 28. In this paper we use inequivalent projections of Hadamard matrices and their symmetric Hamming distances to check inequivalent Hadamard matrices. Using this criterion we developed two algorithms. The first one achieves to find all inequivalent projections in k columns as well as to classify Hadamard matrices and the second, which is faster than the first, uses the sym, metric Hamming distance distribution of projections to classify Hadamard matrices. As an example, we apply the second algorithm to the known inequivalent Hadamard matrices of orders n = 4,8,12,16,20,24 and 28.	en
heal.publisher	CHARLES BABBAGE RES CTR	en
heal.journalName	Ars Combinatoria	en
dc.identifier.isi	ISI:000186007800007	en
dc.identifier.volume	69	en
dc.identifier.spage	79	en
dc.identifier.epage	95	en