DMTCS

Volume 8

n° 1 (2006), pp. 97-120

author:Ed Hong
title:The Online Specialization Problem
keywords:online algorithms, competitive analysis, specializations
abstract:We study the online specialization problem, where items arrive in an online fashion for processing by one of
n
different methods. Each method has two costs: a processing cost (paid once for each item processed), and a set-up cost (paid only once, on the method's first use). There are
n
possible types of items; an item's type determines the set of methods available to process it. Each method has a different degree of specialization. Highly specialized methods can process few item types while generic methods may process all item types. This is a generalization of ski-rental and closely related to the capital investment problem of Y. Azar, Y. Bartal, E. Feuerstein, A. Fiat, S. Leonardi, and A. Rosen. On capital investment. In Algorithmica, 25(1):22-36, 1999.. We primarily study the case where method
i+1
is always more specialized than method
i
and the set-up cost for a more specialized method is always higher than that of a less specialized method. We describe an algorithm with competitive ratio
O(log(n))
, and also show an
Ω(log(n))
lower bound on the competitive ratio for this problem; this shows our ratio is tight up to constant factors.
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reference: Ed Hong (2006), The Online Specialization Problem, Discrete Mathematics and Theoretical Computer Science 8, pp. 97-120
bibtex:For a corresponding BibTeX entry, please consider our BibTeX-file.
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