LIPIcs.TIME.2024.11.pdf
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Faster Algorithm for Converting an STNU into Minimal Dispatchable Form
Authors
Luke Hunsberger 
,
Roberto Posenato
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31st International Symposium on Temporal Representation and Reasoning (TIME 2024)
Series: Leibniz International Proceedings in Informatics (LIPIcs)
Conference: International Symposium on Temporal Representation and Reasoning (TIME) - License:
Creative Commons Attribution 4.0 International license
- Publication Date: 2024-10-22
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Luke Hunsberger and Roberto Posenato. Faster Algorithm for Converting an STNU into Minimal Dispatchable Form. In 31st International Symposium on Temporal Representation and Reasoning (TIME 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 318, pp. 11:1-11:14, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)
https://doi.org/10.4230/LIPIcs.TIME.2024.11
https://doi.org/10.4230/LIPIcs.TIME.2024.11
Abstract
A Simple Temporal Network with Uncertainty (STNU) is a data structure for representing and reasoning about temporal constraints on activities, including those with uncertain durations. An STNU is dispatchable if it can be flexibly and efficiently executed in real time while guaranteeing that all relevant constraints are satisfied. The number of edges in a dispatchable network affects the computational work that must be done during real-time execution. Recent work presented an O(k n³)-time algorithm for converting a dispatchable STNU into an equivalent dispatchable network having a minimal number of edges, where n is the number of timepoints and k is the number of actions with uncertain durations. This paper presents a modification of that algorithm, making it an order of magnitude faster, down to O(n³). Given that in typical applications k = O(n), this represents an effective order-of-magnitude reduction from O(n⁴) to O(n³).
Subject Classification
ACM Subject Classification
- Computing methodologies → Temporal reasoning
- Theory of computation → Dynamic graph algorithms
Keywords
- Temporal constraint networks
- dispatchable networks
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References
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