Abstract
Conditional Temporal Problems (CTPs) can deal simultaneously with uncertainty and temporal constraints, allowing for the representation of temporal and conditional plans. CTPPs generalize CTPs by adding preferences to the temporal constraints and by allowing fuzzy thresholds for the occurrence of some events. Here we focus on dynamic consistency of CTPPs, the most useful notion of consistency in practice. We describe an algorithm which allows for testing if a CTPP is dynamically consistent and we study its complexity. Simple temporal problems with preferences and uncertainty (STPPUs) are another formalism to model temporal constraints where preference and uncertainty coexist. While uncertainty is CTPPs is modeled via conditions on the execution of variables, in STPPUs it is modelled by means of events whose occurrence time is not known. We consider the relation between CTPPs and STPPUs and we show that the former framework is at least as expressive as the second one. Such a result is obtained by providing a polynomial mapping from STPPUs to CTPPs.
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Ai-Chang M., Bresina J.L., Charest L., Chase A., Jung Hsu J.C., Jónsson A.K. et al (2004) MAPGEN: Mixed-initiative planning and scheduling for the Masrs exploration rover mission. IEEE Intelligent Systems 19(1): 8–12
Combi, C., & Pozzi, G. (2006). Task scheduling for a temporal workflow management system. In Proceedings of TIME’06 (pp. 61–68).
Dechter, R. (2003). Constraint processing. Morgan Kaufmann.
Dechter R., Meiri I., Pearl J. (1991) Temporal constraint networks. Artificial Intelligence 49: 61–95
Dubois D., Fargier H., Prade H. (1996) Possibility theory in constraint satisfaction problems: Handling priority, preference and uncertainty. Applied Intelligence 6: 287–309
Falda, M., Rossi, F., & Venable, K. B. (2007a). Fuzzy conditional temporal problems: Dynamic consistency and comparison with STPPUs. In Proceedings of CAEPIA 2007, Workshop on planning, scheduling and constraints satisfaction (pp. 57–68).
Falda, M., Rossi, F., & Venable, K. B. (2007b). Strong, weak, and dynamic consistency in fuzzy conditional temporal problems. In Proceedings of CSCLP 2007 (pp. 187–201).
Falda, M., Rossi, F., & Venable, K. B. (2007c). Strong, weak, and dynamic consistency in fuzzy conditional temporal problems. In Proceedings of COPLAS 2007, CP’07 workshop on planning and scheduling.
Khatib, L., Morris, P., Morris, R. A., & Rossi, F. (2001). Temporal constraint reasoning with preferences. In IJCAI01 (pp. 322–327).
Peintner, B., & Pollack, M. E. (2004). Low-cost addition of preferences to DTPs and TCSPs. In Proceedings of AAAI’-04 (pp. 723–728). AAAI Press/The MIT Press.
Pollack M.E., Brown L.E., Colbry D., McCarthy C.E., Orosz C., Peintner B. et al (2003) Autominder: An intelligent cognitive orthotic system for people with memory impairment. Robotics and Autonomous Systems 44(3–4): 273–282
Rossi F., Venable K.B., Yorke-Smith N. (2006) Uncertainty in soft temporal constraint problems: A general framework and controllability algorithms for the fuzzy case. Journal of AI Research 27: 617–674
Stergiou K., Koubarakis M. (2000) Backtracking algorithms for disjunctions of temporal constraints. Artificial Intelligence 120(1): 81–117
Tsamardinos, I. (2001). Constraint-based temporal reasoning algorithms with applications to planning. Ph.D. thesis, University of Pittsburgh.
Tsamardinos I., Pollack M.E. (2003) Efficient solution techniques for disjunctive temporal reasoning problems. Artificial Intelligence 151(1–2): 43–89
Tsamardinos I., Vidal T., Pollack M.E. (2003) CTP: A new constraint-based formalism for conditional, temporal planning. Constraints 8(4): 365–388
Vidal T., Fargier H. (1999) Handling contigency in temporal constraint networks. Journal of Experimental and Theoretical Artificial Intelligence Research 11(1): 23–45
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Falda, M., Rossi, F. & Venable, K.B. Dynamic consistency of fuzzy conditional temporal problems. J Intell Manuf 21, 75–88 (2010). https://doi.org/10.1007/s10845-008-0170-9
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DOI: https://doi.org/10.1007/s10845-008-0170-9