New quasi-symmetric designs by the Kramer–Mesner method
نویسندگان
چکیده
منابع مشابه
New quasi-symmetric designs by the Kramer-Mesner method
A t-(v, k, λ) design is quasi-symmetric if there are only two block intersection sizes. We adapt the Kramer-Mesner construction method for designs with prescribed automorphism groups to the quasi-symmetric case. Using the adapted method, we find many new quasi-symmetric 2-(28, 12, 11) and 2-(36, 16, 12) designs, establish the existence of quasi-symmetric 2-(56, 16, 18) designs, and find three n...
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A quasi-symmetric design is a (v, k, λ) design with two intersection numbers x, y where 0 ≤ x < y < k. We show that for fixed x, y, λ with x > 1, λ > 1, y = λ and λ (4xy + ((y − x) − 2x− 2y + 1)λ) a perfect square of a positive integer, there exist finitely many quasi-symmetric designs. We rule out the possibilities of quasi-symmetric designs corresponding to y = x + 3 and (λ, x) = (9, 2), (8, ...
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ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 2016
ISSN: 0012-365X
DOI: 10.1016/j.disc.2016.05.030