{"type":"ScholarlyArticle","title":"Optimistic Parallel biscrete Relaxation","authors":[{"name":"Kinson Ho","slug":"kinson-ho","given":"Kinson","family":"Ho","affiliation":""},{"name":"Paul N. Hilfinger","slug":"paul-n-hilfinger","given":"Paul N.","family":"Hilfinger","affiliation":""},{"name":"Hans W. Guesgen","slug":"hans-w-guesgen","given":"Hans W.","family":"Guesgen","affiliation":""}],"abstract":"Discrete relaxation is frequently used to compute the fixed point of a discrete system X= /(X), where f is monotonic with respect to some partial order $. Given an appropriate initial value for X, discrete relaxation repeats the assignment X - /(X) until a fixed point for f is found. Monotonicity of f with respect to $ is a sufficient (but in general not necessary) condition for iterative, hill-climbing techniques such as discrete relaxation to find the fixed point of f. In this paper we introduce monotonic asynchronous iteration as a novel way of implementing parallel discrete relaxation in problem domains for which monotonicity is a necessary condition. This is an optimistic technique that maintains monotonicity without limiting concurrency, resulting in good parallel performance. We illustrate this technique with the parallel implementation of a constraint satisfaction system that computes globally consistent solutions, and present performance numbers for experiments on a shared-memory implementation. The performance numbers show that it is indeed possible to obtain a reasonable speedup when parallelizing global constraint satisfaction. We believe that monotonic asynchronous iteration is applicable to parallel discrete relaxation in general.","doi":null,"url":"https://ijcai.org/proceedings/1993/38","pdf":"https://ijcai.org/proceedings/1993/0038.pdf","markdown":"https://ijcai.org/proceedings/1993/38.md","bibtex":"https://ijcai.org/proceedings/1993/bibtex/38","volume":{"slug":"1993","title":"Proceedings of the Thirteenth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 1993","url":"https://ijcai.org/proceedings/1993/","year":1993,"location":"Chambéry, France","dates":"","editors":"Ruzena Bajcsy","isbn":"","publisher":"International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":"Constraint Satisfaction Problems","track":"Constraint Satisfaction Problems","number":38,"pages":{"first":268,"last":274},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}