منابع مشابه
Combinatorics of Periods in Strings
We consider the set Γ (n) of all period sets of strings of length n over a finite alphabet. We show that there is redundancy in period sets and introduce the notion of an irreducible period set. We prove that Γ (n) is a lattice under set inclusion and does not satisfy the JordanDedekind condition. We propose the first enumeration algorithm for Γ (n) and improve upon the previously known asympto...
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The study of approximately periodic strings is relevant to diverse applications such as molecular biology data compression and computer assisted music analysis Here we study di erent forms of ap proximate periodicity under a variety of distance rules We consider three related problems for two of which we derive polynomial time algorithms we then show that the third problem is NP complete
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The article is an overview of basic issues related to repetitions in strings, concentrating on algorithmic and combinatorial aspects. This area is important both from theoretical and practical point of view. Repetitions are highly periodic factors (substrings) in strings and are related to periodicities, regularities, and compression. The repetitive structure of strings leads to higher compress...
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Approximate periods of strings can be used to find approximate repetitive regularities in strings. In this paper we consider the approximate period problem for different absolute distances.
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The counting of long strings in ADS3, in the context of Type IIB string theory on ADS3 × S × T , is used to exhibit the action of the duality group O(5, 5;Z), and in particular its Weyl Subgroup S5 ⊲⊳ Z2, in the non-perturbative phenomena associated with continuous spectra of states in these backgrounds. The counting functions are related to states in Fock spaces. The symmetry groups also appea...
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ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series A
سال: 2003
ISSN: 0097-3165
DOI: 10.1016/s0097-3165(03)00123-7