On the consistency of cardinal direction constraints

Skiadopoulos, S; Koubarakis, M

dc.contributor.author	Skiadopoulos, S	en
dc.contributor.author	Koubarakis, M	en
dc.date.accessioned	2014-03-01T01:22:51Z
dc.date.available	2014-03-01T01:22:51Z
dc.date.issued	2005	en
dc.identifier.issn	0004-3702	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16688
dc.subject	Cardinal direction relations	en
dc.subject	Consistency checking	en
dc.subject	Qualitative spatial reasoning	en
dc.subject	Spatial constraints	en
dc.subject.classification	Computer Science, Artificial Intelligence	en
dc.subject.other	Algorithms	en
dc.subject.other	Computational complexity	en
dc.subject.other	Mathematical models	en
dc.subject.other	Multimedia systems	en
dc.subject.other	Problem solving	en
dc.subject.other	Topology	en
dc.subject.other	Cardinal direction relations	en
dc.subject.other	Consistency checking	en
dc.subject.other	Qualitative spatial reasoning	en
dc.subject.other	Spatial constraints	en
dc.subject.other	Constraint theory	en
dc.title	On the consistency of cardinal direction constraints	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.artint.2004.10.010	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.artint.2004.10.010	en
heal.language	English	en
heal.publicationDate	2005	en
heal.abstract	We present a formal model for qualitative spatial reasoning with cardinal directions utilizing a coordinate system. Then, we study the problem of checking the consistency of a set of cardinal direction constraints. We introduce the first algorithm for this problem, prove its correctness and analyze its computational complexity. Utilizing the above algorithm, we prove that the consistency checking of a set of basic (i.e., non-disjunctive) cardinal direction constraints can be performed in O(n(5)) time. We also show that the consistency checking of a set of unrestricted (i.e., disjunctive and non-disjunctive) cardinal direction constraints is NP-complete. Finally, we briefly discuss an extension to the basic model and outline an algorithm for the consistency checking problem of this extension. (C) 2004 Elsevier B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Artificial Intelligence	en
dc.identifier.doi	10.1016/j.artint.2004.10.010	en
dc.identifier.isi	ISI:000226849600004	en
dc.identifier.volume	163	en
dc.identifier.issue	1	en
dc.identifier.spage	91	en
dc.identifier.epage	135	en