Fault tolerance by means of external monitoring of computer systems
AFIPS Conference Proceedings; vol. 55 1986 National Computer Conference
Abstractions of Finite-State Machines Optimal with Respect to Single Undetectable Output Faults
IEEE Transactions on Computers
The art of computer programming, volume 1 (3rd ed.): fundamental algorithms
The art of computer programming, volume 1 (3rd ed.): fundamental algorithms
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
Concurrent Error Detection Using Watchdog Processors-A Survey
IEEE Transactions on Computers
Theories of abstract automata (Prentice-Hall series in automatic computation)
Theories of abstract automata (Prentice-Hall series in automatic computation)
Abstractions of Random Finite-State Machines
Formal Methods in System Design
Research: Signature-based method for run-time fault detection in communication protocols 1
Computer Communications
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A general way to make a smaller model of a large system, or to represent the fact that the observations possible on it are limited, is to apply an abstraction A to it. If the system is modeled by a finite-state machine M, the abstraction consists of three partitions, one for each of the state, input, and output sets. States, inputs, or outputs lumped together in one block by the partition are indistinguishable from each other, resulting in a nondeterministic machine M/sub A/. An observer of M/sub A/, whose task is to detect erroneous behavior in M, is prevented by the abstraction from seeing some of the faults. The authors investigate the choice of an abstraction that is optimal with respect to immediately detectable faults in the output map. It is shown that this requires solving an NP-complete 'set-partitioning' problem. A polynomial-time algorithm for finding an approximately optimal partition of either the states or the inputs of M, together with a way to check the goodness of the approximation is given. This algorithm also solves the undetectable fault minimization problem exactly, and in polynomial time.