Optimizing path real-time logic for unified real-time system

Autor: Huiyou Chang, Xudong Zhu, Kin Fun Li
Rok vydání: 2016
Předmět:
Zdroj: Soft Computing. 21:3135-3145
ISSN: 1433-7479
1432-7643
DOI: 10.1007/s00500-016-2178-y
Popis: By simply describing a classic weakly hard real-time system's performance with the number of tasks meeting or missing deadlines, the system's real-time characteristics cannot be expressed accurately and its reliability cannot be established. The path real-time logic (RTL) is used to determine the reliability of real-time systems; though desirable, it cannot be used as a tool to configure an optimized real-time system. This paper introduces the notion of optimizing path RTL, where integer constants of arithmetic inequality in path RTL are replaced by integer constants or integer variables. With further modifications, optimizing path RTL can not only determine the reliability of a real-time system, but also be used to optimize the system. Furthermore, a unified framework for hard, soft and weakly hard real-time system is established based on optimizing path RTL. The process of transforming a weakly hard real-time system into this unified framework is demonstrated. Moreover, this work proposes and proves a theorem that if the directed ring of a constraint graph contains all elements of behaviour specification (SP) and only SP, then its value must not be greater than zero. This theorem can be used to quickly determine the reliability and safety of a real-time system. A case study is presented to show the validity and reliability of optimizing path RTL and the unified real-time system.
Databáze: OpenAIRE
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