JNTU IV B.Tech I Semester Supplimentary Examinations, February 2008
REAL TIME SYSTEMS
1. (a) Explain the hierarchical decision making function and structure with the help of a figure.
(b) What do you understand by the word ?Distributed Systems?? Elaborate.
2. Explain what the following parts of a Real- Time systems:
(a) Central Processing Unit
(c) Input and Output.
3. Explain in detail, the following concepts
(b) Procedures and Functions
4. (a) Show that the periodic tasks (10,2), (15,5), and (25,9) are schedulable by the rate monotonic algorithm.
(b) Show that the periodic tasks (10,2) (12,5) and (15,4) are not schedulable by the rate monotonic algorithm.
(c) Construct the initial segments in the time interval (0,75) of a rate monotonic schedule and a earliest-deadline-first schedule of the periodic tasks (10,2) (15,5) and (25,12).
5. Explain on RTS development using
(a) Hatley and Phribhai
(b) Ward and Mellor method
6. (a) Explain ACID properties of Database Transactions.
(b) Describe how Petri nets are used to model and analyse mutual exclusion.
7. (a) What are the rules for assigning time stamps to a transaction? Explain.
(b) Explain the method, which can help higher-priority transactions avoid being blocked by lower-priority ones.
8. (a) Discuss different types of software models.
(b) What is the limited usefulness of software error models?
i. What is meant by fault injection? Explain how it is used to measure an error Propagation time.
ii. Explain real life components, which have a hazard rate shaped according to the Bathtub curve.