Dependability and Security

A. System to stop a train if it passes a red light
B. System to indicate not returning of the library book
C. System to shut down a reactor if temperature/pressure are too high
D. None of the mentioned

Explanation: A Protection system is a specialized system that is associated with some other control system, which can take emergency action if a failure occurs.

A. True
B. False

Explanation: Exception handling is a mechanism to provide some fault tolerance.

A. Check that the input does not exceed some maximum size e.g. 40 characters for a name
B. Check that the input falls within a known range
C. Use information about the input to check if it is reasonable rather than an extreme value
D. None of the mentioned

A. True
B. False

Explanation: The answer is self explanatory.

A. Fault Avoidance
B. Fault detection
C. Fault tolerance
D. None of the mentioned

A. Fault Avoidance
B. Fault detection
C. Fault tolerance
D. None of the mentioned

Explanation: In Fault Avoidance, the system is developed in such a way that human error is avoided and thus system faults are minimised.

A. Different programming languages
B. Different design methods and tools
C. Explicit specification of different algorithms
D. All of the mentioned

Explanation: Diversity means to provide the same functionality in different ways so that critical components of a dependable system will not fail in the same way.

A. Diverse
B. Documentable
C. Auditable
D. None of the mentioned

Explanation: It means that process standards are being followed and make suggestions for process improvement.

A. Medical Systems
B. Power Systems
C. Library Management
D. Telecommunications

Explanation: Software customers expect all software to be dependable. However, for non-critical applications such as certain management systems, they may be willing to accept some system failures.

A. Loss of service
B. Incorrect service delivery
C. System/data corruption
D. None of the mentioned