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Mathematical Sciences Seminar - k-Radius Sequences

When:
Venue: Birkbeck Main Building, Malet Street

No booking required

(Joint work with James McKee.)

A k-radius sequence is a finite sequence over an alphabet of size n, with the property that every two alphabet symbols occur within a distance of k of each other somewhere in the sequence. We write fk(n) for the shortest n-ary k-radius sequence. Jaromczyk and Lonc introduced this concept in 2004: they were interested in designing a (first-in first-out) caching strategy for computations involving pairs of large data objects such as medical images.

In this talk, I will start by talking a little about the caching application. I'll then show how to prove that fk(n) grows like (1/k)(n(n-1)/2) when k is fixed and n goes to infinity.

This talk is based on the following papers:

S.R. Blackburn, 'The existence of k-radius sequences'. See http://arxiv.org/abs/1101.1172

S.R. Blackburn and J.F. McKee, 'Constructing k-radius sequences', Mathematics of Computation, to appear. See http://arxiv.org/abs/1006.5812

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