We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Extending the accommodating function.
- Authors
Boyar, Joan; Favrholdt, Lene M.; Larsen, Kim S.; Nielsen, Morten N.
- Abstract
The applicability of the accommodating function, a relatively new measure for the quality of on-line algorithms, is extended. The standard quality measure for on-line algorithms is the competitive ratio, which is, roughly speaking, the worst case ratio of the on-line performance to the optimal off-line performance. However, for many on-line problems, the competitive ratio gives overly pessimistic results and/or fails to distinguish between algorithms that are known to perform very differently in practice. Many researchers have proposed variations on the competitive ratio to obtain more realistic results. These variations are often tailor-made for specific on-line problems. The concept of the accommodating function applies to any on-line problem with some limited resource, such as bins, seats in a train, or pages in a cache. If a limited amount n of some resource is available, the accommodating function A(α) is the competitive ratio when input sequences are restricted to those for which the amount αn of resources suffices for an optimal off-line algorithm. For all resource bounded problems, the standard competitive ratio is lim[subα→∞A(α). The accommodating function was originally used only for We focus on α < 1, observe that the function now appears interesting for a greater variety of problems, and use it to make new distinctions between known algorithms and to find new ones.
- Subjects
POLAR forms (Mathematics); BRANCH &; bound algorithms; COMPUTER algorithms; ONLINE algorithms
- Publication
Acta Informatica, 2003, Vol 40, Issue 1, p3
- ISSN
0001-5903
- Publication type
Article
- DOI
10.1007/s00236-003-0124-9