{"type":"ScholarlyArticle","title":"Simpler and Faster Algorithm for Checking the Dynamic Consistency of Conditional Simple Temporal Networks","authors":[{"name":"Luke Hunsberger","slug":"luke-hunsberger","given":"Luke","family":"Hunsberger","affiliation":"Department of Computer Science Vassar College , USA"},{"name":"Roberto Posenato","slug":"roberto-posenato","given":"Roberto","family":"Posenato","affiliation":"Department of Computer Science University of Verona , Italy"}],"abstract":"Recent work on Conditional Simple Temporal Networks (CSTNs) has\r\nfocused on checking the dynamic consistency (DC) property assuming\r\nthat execution strategies can react instantaneously to observations.\r\nThree alternative semantics---IR-DC, 0-DC, and π-DC---have been presented.  \r\nThe most practical DC-checking algorithm for CSTNs has only been analyzed \r\nwith respect to the IR-DC semantics, while the 0-DC semantics was shown to have a serious flaw\r\nthat the π-DC semantics fixed.  Whether the IR-DC semantics had\r\nthe same flaw and, if so, what the consequences would be for the\r\nDC-checking algorithm remained open questions.\r\n\r\nThis paper (1) shows that the IR-DC semantics is also flawed; \r\n(2) shows that one of the constraint-propagation rules from \r\nthe IR-DC-checking algorithm is not sound with respect to the IR-DC\r\nsemantics; \r\n(3) presents a simpler algorithm, called the π-DC-checking algorithm; \r\n(4) proves that it is sound and complete with respect to the π-DC semantics; \r\nand (5) empirically evaluates the new algorithm.","doi":"10.24963/ijcai.2018/184","url":"https://ijcai.org/proceedings/2018/184","pdf":"https://ijcai.org/proceedings/2018/0184.pdf","markdown":"https://ijcai.org/proceedings/2018/184.md","bibtex":"https://ijcai.org/proceedings/2018/bibtex/184","volume":{"slug":"2018","title":"Proceedings of the Twenty-Seventh International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2018","url":"https://ijcai.org/proceedings/2018/","year":2018,"location":"Stockholm","dates":"13-19 July 2018","editors":"Jérôme Lang","isbn":"978-0-9992411-2-7","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2018"},"section":"Constraints and SAT","track":"Main track","number":184,"pages":{"first":1324,"last":1330},"keywords":["Constraints and SAT: Constraint Satisfaction","Knowledge Representation and Reasoning: Geometric, Spatial, and Temporal Reasoning","Constraints and SAT: Constraints: Evaluation and Analysis"],"videos":[],"references":[{"position":1,"raw":"[Cairo et al., 2016] Massimo Cairo, Carlo Comin, and Romeo Rizzi. Instantaneous reaction-time in dynamic- consistency checking of conditional simple temporal net- works. In TIME 2016, 2016.","title":"Instantaneous reaction-time in dynamic-consistency checking of conditional simple temporal networks","authors":"Massimo Cairo, Carlo Comin, Romeo Rizzi","year":"2016","venue":"TIME 2016","doi":null,"url":null,"internal_url":null},{"position":2,"raw":"[Cairo et al., 2017] Massimo Cairo, Luke Hunsberger, Roberto Posenato, and Romeo Rizzi. A Streamlined Model of Conditional Simple Temporal Networks -Semantics and Equivalence Results. In 24th International Symposium on Temporal Representation and Reasoning (TIME 2017), volume 90 of LIPIcs, pages 10:1-10:19, 2017.","title":"A Streamlined Model of Conditional Simple Temporal Networks -Semantics and Equivalence Results","authors":"Massimo Cairo, Luke Hunsberger, Roberto Posenato, Romeo Rizzi","year":"2017","venue":"24th International Symposium on Temporal Representation and Reasoning (TIME 2017)","doi":null,"url":null,"internal_url":null},{"position":3,"raw":"[Cimatti et al., 2014] A. Cimatti, L. Hunsberger, A. Micheli, R. Posenato, and M. Roveri. Sound and complete algo- rithms for checking the dynamic controllability of temporal networks with uncertainty, disjunction and observation. In 21st International Symposium on Temporal Representation and Reasoning (TIME 2014), pages 27-36. IEEE, 2014.","title":"Sound and complete algorithms for checking the dynamic controllability of temporal networks with uncertainty, disjunction and observation","authors":"A Cimatti, L Hunsberger, A Micheli, R Posenato, M Roveri","year":"2014","venue":"21st International Symposium on Temporal Representation and Reasoning (TIME 2014)","doi":null,"url":null,"internal_url":null},{"position":4,"raw":"[Cimatti et al., 2016] A. Cimatti, L. Hunsberger, A. Micheli, R. Posenato, and M. Roveri. Dynamic controllability via Timed Game Automata. Acta Informatica, 53(6-8):681- 722, 2016.","title":"Dynamic controllability via Timed Game Automata","authors":"A Cimatti, L Hunsberger, A Micheli, R Posenato, M Roveri","year":"2016","venue":"Acta Informatica","doi":null,"url":null,"internal_url":null},{"position":5,"raw":"[Comin and Rizzi, 2015] Carlo Comin and Romeo Rizzi. Dy- namic consistency of conditional simple temporal networks via mean payoff games: a singly-exponential time dc- checking. In 22st International Symposium on Temporal Representation and Reasoning (TIME 2015), pages 19-28. IEEE, 2015.","title":"Carlo Comin and Romeo Rizzi. Dynamic consistency of conditional simple temporal networks via mean payoff games: a singly-exponential time dcchecking","authors":"Rizzi Comin","year":"2015","venue":"22st International Symposium on Temporal Representation and Reasoning (TIME 2015)","doi":null,"url":null,"internal_url":null},{"position":6,"raw":"[Dechter et al., 1991] Rina Dechter, Itay Meiri, and Judea Pearl. Temporal constraint networks. Artificial Intelligence, 49(1-3):61-95, 1991.","title":"Temporal constraint networks","authors":"Rina Dechter, Itay Meiri, Judea Pearl","year":"1991","venue":"Artificial Intelligence","doi":null,"url":null,"internal_url":null},{"position":7,"raw":"[Hunsberger and Posenato, 2016] Luke Hunsberger and Roberto Posenato. Checking the Dynamic Consistency of Conditional Temporal Networks with Bounded Reaction Times. In Proceedings of the 26th International Conference on Automated Planning and Scheduling, ICAPS 2016, pages 175-183, 2016.","title":"Checking the Dynamic Consistency of Conditional Temporal Networks with Bounded Reaction Times","authors":"Posenato Hunsberger, Luke Hunsberger, Roberto Posenato","year":"2016","venue":"Proceedings of the 26th International Conference on Automated Planning and Scheduling, ICAPS 2016","doi":null,"url":null,"internal_url":null},{"position":8,"raw":"[Hunsberger et al., 2012] Luke Hunsberger, Roberto Posen- ato, and Carlo Combi. The Dynamic Controllability of Conditional STNs with Uncertainty. In PlanEx at ICAPS 2012, pages 1-8, 2012.","title":"The Dynamic Controllability of Conditional STNs with Uncertainty","authors":"Hunsberger","year":"2012","venue":"PlanEx at ICAPS 2012","doi":null,"url":null,"internal_url":null},{"position":9,"raw":"[Hunsberger et al., 2015] Luke Hunsberger, Roberto Posen- ato, and Carlo Combi. A sound-and-complete propagation- based algorithm for checking the dynamic consistency of conditional simple temporal networks. In 22st International Symposium on Temporal Representation and Reasoning (TIME 2015), pages 4-18. IEEE, 2015.","title":"A sound-and-complete propagationbased algorithm for checking the dynamic consistency of conditional simple temporal networks","authors":"Hunsberger","year":"2015","venue":"22st International Symposium on Temporal Representation and Reasoning (TIME 2015)","doi":null,"url":null,"internal_url":null},{"position":10,"raw":"[Lanz and Reichert, 2014] Andreas Lanz and Manfred Re- ichert. Enabling time-aware process support with the AT- APIS Toolset. In Proceedings of the BPM Demo Sessions 2014, volume 1295, pages 41-45, 2014.","title":"Enabling time-aware process support with the AT-APIS Toolset","authors":"Reichert Lanz","year":"1295","venue":"Proceedings of the BPM Demo Sessions 2014","doi":null,"url":null,"internal_url":null},{"position":11,"raw":"[Posenato, 2017] Roberto Posenato. A CSTN(U) consistency check algorithm implementation in Java. Version 1.20. http://profs.scienze.univr.it/∼posenato/software/cstnu, November 2017.","title":"A CSTN(U) consistency check algorithm implementation in Java","authors":"Roberto Posenato","year":"2017","venue":null,"doi":null,"url":"http://profs.scienze.univr.it/∼posenato/software/cstnu","internal_url":null},{"position":12,"raw":"[Tsamardinos et al., 2003] Ioannis Tsamardinos, Thierry Vi- dal, and Martha E. Pollack. CTP: A new constraint-based formalism for conditional, temporal planning. Constraints, 8:365-388, 2003.","title":"CTP: A new constraint-based formalism for conditional, temporal planning","authors":"Ioannis Tsamardinos, Thierry Vidal, Martha E Pollack","year":"2003","venue":"Constraints","doi":null,"url":null,"internal_url":null}],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}