TASK PARAMETER IMPACTS IN FUZZY REAL TIME SCHEDULING

Öz

The classical analysis of real-time systems tries to ensure that the instance of every task nishes before its absolute deadline (strict guarantee). The probabilistic approach tends to estimate the probability that it will happen. The deterministic timed behaviour is an important parameter for analysing the robustness of the system. Most of related works are mainly based on the determinism of time constraints. However, in most cases, these parameters are non-precise. The vagueness of parameters suggests the use of fuzzy logic to decide in what order the requests should be executed to reduce the chance of a request being missed. The choice of task parameters and numbers of rules in fuzzy inference engine in uences directly generated outputs. Our main contribution is proposing a fuzzy approach to perform real-time scheduling in which the scheduling parameters are treated as fuzzy variables. A comparison of the results of the use of each parameter as linguistic variable is also given.

Anahtar Kelimeler

• Fuzzy logic,Real-time task,Fuzzy Inference Engine,Fuzzy real-time scheduling,Task parameters

Kaynakça

1. Sha, L. a. Real-Time Scheduling Theory and Ada, (1990). IEEE Computer, Vol. 23, No. 4, pp. 53-62.
2. Ramamnitham K., s. J. (1994). Scheduling algorithms and operating systems. Proceedings of IEEE, vol 82, No1, pp 55-67.
3. Layland, C. L. (1973). Scheduling alghorithms for multiprogramming systems. Journal of the ACM, 20 (1).
4. J. Zhu, T. G. Scheduling in hard real-time applications. (1994). IEEE Softw, vol 12, pp. 54-63.
5. Haibin, W. L. (2003). Research on a soft real-time scheduling algorithm based on hybrid adaptive control architecture. Proc. American Control Conf, Lisbon, Portugal, pp. 4022-4027 Vol.5.
6. Tarek. F. Abdelzaher and K. G. Shin. (1997). Comment on a pre-runtime scheduling algorithm for hard realtime systems. IEEE Trans Software Engineering, Vol. 23, pp. 599-600.
7. Ramamritham, K. and Stankovic, J.A. (1984). Dynamic task scheduling in hard real-time distributed systems. IEEE Softw, vol. 1, pp. 65-75.
8. P. A. Laplante (2004). The certainty of uncertainty in real-time systems. IEEE Instrum. Meas. Mag, vol. 7, pp. 44-50.

9. Kreuzinger, A.S (2000). Real-time scheduling on multithreaded. Proc. 7th Intl. Conf. Real-Time Computing Systems, Cheju Island, South Korea, pp. 155-159.
10. Z. Deng, J. W, (1996). Dynamic scheduling of hard realtime applications in open system environment. Tech. Rep. University of Illinois at Urbana-Champaign.