منابع مشابه
Almost all webs are not rank-perfect
Graphs with circular symmetry, called webs, are relevant w.r.t. describing the stable set polytopes of two larger graph classes, quasi-line graphs [8,12] and claw-free graphs [7,8]. Providing a decent linear description of the stable set polytopes of claw-free graphs is a long-standing problem [9]. Ben Rebea conjectured a description for quasi-line graphs, see [12]; Chudnovsky and Seymour [2] v...
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Graphs with circular symmetry, called webs, are relevant w.r.t. describing the stable set polytopes of two larger graph classes, quasi-line graphs [7,11] and claw-free graphs [6,7]. Providing a decent linear description of the stable set polytopes of claw-free graphs is a long-standing problem [8]. However, even the problem of finding all facets of stable set polytopes of webs is open. So far, ...
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We discuss a nested collection of three superclasses of perfect graphs: near-perfect, rank-perfect, and weakly rank-perfect graphs. For that we start with the description of the stable set polytope for perfect graphs and allow stepwise more general facets for the stable set polytopes of the graphs in each superclass. Membership in those three classes indicates how far a graph is away from being...
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We construct a perfect extrinsic secret sharing scheme for any case in which a set of participants can gain access to the secret if and only if the set contains a pair of members from some given list of pairs. A secret sharing scheme is a way by which a dealer rnay distribute secret information to individuals (call participants). There is associated '-<U.lh'.lcH"""F-of subsets of a set of can i...
متن کاملAlmost All Palindromes Are Composite
We study the distribution of palindromic numbers (with respect to a fixed base g ≥ 2) over certain congruence classes, and we derive a nontrivial upper bound for the number of prime palindromes n ≤ x as x → ∞. Our results show that almost all palindromes in a given base are composite. ∗MSC Numbers: 11A63, 11L07, 11N69 †Corresponding author 1
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ژورنال
عنوان ژورنال: Mathematical Programming
سال: 2005
ISSN: 0025-5610,1436-4646
DOI: 10.1007/s10107-005-0655-7