A COMPARATIVE STUDY OF FUZZIFIED CPU SCHEDULING POLICIES IN REAL TIME SYSTEM
Section 3 : Fuzzy triangular and trapezoidal membership function.
4. Comparative Study:
Priority scheduling algorithms, First come First serve (FCFS) and Shortest Job First (SJF) have been implemented and the comparative study is made and in this paper we have discussed the benchmarks among these algorithms and the concluding benchmarks are made on these basis. The results obtained after comparison of these algorithms are shown in the Tables 6-8.The analysis are done for both triangular and trapezoidal membership functions for the defuzzified values of the burst time.
Table 6: Comparison of Average Waiting & Turnaround Time in Triangular Fuzzy Environment Total Processes=12(ASCENDING SORTED CPU BURST)
A Comparative study of Fuzzified CPU Scheduling Policies in Real Time System
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Graph4:Average Turnaround Time for triangular in ascending order
Table 7: Comparison of Average Waiting & Turnaround Time in Triangular Fuzzy Environment Total Processes=12(RANDOM SORTED CPU BURST)
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Graph6:Average Turnaround Time for triangular in random order
Table 8: Comparison of Average Waiting & Turnaround Time in Triangular Fuzzy Environment Total Processes=12(DESCENDING SORTED CPU BURST)
Graph7:Average Waiting Time for triangular in descending order
Graph 8 :Average Turnaround Time for triangular in descending order
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Total Processes=12(ASCENDING SORTED CPU BURST)
Graph9:Average waiting Time for trapezoidal in ascending order
Graph10:Average Turnaround Time for trapezoidal in ascending order
Table 10: Comparison of Average Waiting & Turnaround Time in Trapezoidal Fuzzy Environment Total Processes=12(RANDOM SORTED CPU BURST)
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Table 11: Comparison of Average Waiting & Turnaround Time in Trapezoidal Fuzzy system
Graph 12:Average waiting Time for trapezoidal in random order
Graph 13:Average Turnaround Time for trapezoidal in random order
Table11:Comparison of Average waiting time and turn around time in trapezoidal fuzzy system Total Processes=12(DESCENDING SORTED CPU BURST)
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Graph13:Average waiting Time for trapezoidal in descending order
Graph14:Average Turnaround Time for trapezoidal in descending order 5. Result Analysis:
First come First serve(FCFS),SJF,Priority,Round Robin have been calculated for the 12 processes. These scheduling algorithms have been implemented through graphs. The results obtained after comparative study have been presented in tables 6-11 taking variable time quanta for round robin algorithm.The analytical study has been made for both triangular and trapezoidal functions for the defuzzified value of burst time.We have shown the output of different scheduling policies through Bar Diagram.The fuzzy model design for comparative study of CPU Scheduling policies has also been depicted through Bar Diagram.
6. Conclusion and Further Scope
The analytical study for various policies through Bar graph shows that the average waiting time as well as average turnaround time of scheduling policies from FCFS, SJF, Priority and Round Robin gradually increases as depicted . It is because FCFS algorithm depends upon the order of the Burst Time of Processes lined up in a Queue. This further applies that if special hardware is attached to the CPU to sort the process in order of their Burst time
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whether in ascending order, descending order or random selection, the SJF policy gives almost a constant value of average waiting time and turnaround time in both triangular and trapezoidal cases which is minimum than other policies. It also maximize the CPU throughput. We conclude that SJF is best policy while Round Robin takes more time than other policies.
The work can be extended by taking multi processor on dividing the ready Queue into parts.Further work can be done by considering time quanta in Fuzzy logics.
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Aryabhatta Journal of Mathematics & Informatics Vol. 7, No. 1, Jan-June, 2015 ISSN : 0975-7139
Scientific Journal Impact Factor SJIF (2014) : 4.1