On families of finite sets no two of which intersect in a singleton
نویسندگان
چکیده
منابع مشابه
Families of Finite Sets in Which No Set Is Covered by the Union of Two Others
Let f k (n) denote the maximum of k-subsets of an n-set satisfying the condition in the title. It is proven that f"(n) < f"(n + 1) < with equalities holding iff there exists a Steiner-system Y(t, 2t-1, n). The bounds are approximately best possible for k < 6 and of correct order of magnitude for k > 7, as well, even if the corresponding Steiner-systems do not exist. Exponential lower and upper ...
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چکیده ندارد.
15 صفحه اولFAMILIES OF FINITE SETS IN WHICH NO SET IS COVERED BY THE UNION OF r OTHERS'
Let f,(n, k) denote the maximum number of k-subsets of an n-set satisfying the condition in the title . It is proved that f,(n,r(t-1)+1+d)-(n t dl/ u lk t dl for n sufficiently large whenever d = 0,1 or d < r/2 t 2 withJh equality holding iff there exists a Steiner system S(t, r(t 1) + l, n d). The determination of f,(n, 2r) led us to a new generalization of BIRD (Definition 2 .4). Exponential ...
متن کاملFamilies of Finite Sets in which No Intersection of Sets Is Covered by the Union of s Others
In 1964, Kautz and Singleton (IEEE Trans. Inform. Theory 10 (1964), 363–377) introduced the superimposed code concept. A binary superimposed code of strength s is identified by the incidence matrix of a family of finite sets in which no set is covered by the union of s others (J. Combin. Theory Ser. A 33 (1982), 158–166 and Israel J. Math. 51 (1985), 75–89). In the present paper, we consider a ...
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terms of address as an important linguistics items provide valuable information about the interlocutors, their relationship and their circumstances. this study was done to investigate the change route of persian address terms in the two recent centuries including three historical periods of qajar, pahlavi and after the islamic revolution. data were extracted from a corpus consisting 24 novels w...
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ژورنال
عنوان ژورنال: Bulletin of the Australian Mathematical Society
سال: 1977
ISSN: 0004-9727,1755-1633
DOI: 10.1017/s0004972700025521