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Lookup NU author(s): Professor Aad van Moorsel
Uniformization has been shown to be, in many cases, a good method to compute transient state probabilities of a continuous-time Markov chain. However, two issues limit its use: uniformization can be computationally very intensive, for instance, on stiff models, and uniformization cannot be used for all model classes, e.g., models with not uniformly bounded transition rates. In this paper we introduce adaptive uniformization a variation on standard uniformization, which can overcome these problems for some models. Adaptive uniformization differs from standard uniformization in that it uses a uniformization rate that adapts depending on the set of states that the process can be in after a particular number of jumps. Doing this can sometimes significantly reduce the computational cost required to obtain a solution. A formal definition of adaptive uniformization is first given, along with a proof that adaptive uniformization yields correct results. Characteristics of models that can facilitate solution and alternative methods for computing the required “jump probabilities” are then discussed. Finally, the computational cost of adaptive uniformization (relative to standard uniformization) is illustrated, through its application to an extended machine-repairman model.
Author(s): van Moorsel A, Sanders WH
Publication type: Article
Publication status: Published
Journal: Communications in Statistics: Stochastic Models
Year: 1994
Volume: 10
Issue: 3
Pages: 619-648
Date deposited: 06/12/2011
ISSN (print): 0882-0287
ISSN (electronic): 1532-4214
Publisher: Dekker
URL: http://dx.doi.org/10.1080/15326349408807313
DOI: 10.1080/15326349408807313
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