David Jerald Goldstone
A system, called Skordos, has been implemented for model-based diagnosis of analog circuits. One of the difficulties of model-based diagnosis of analog circuits is managing the tremendous number of predictions which may be generated by a constraint propagation system. Fortunately, not all of those predictions are valuable for the diagnostic process. A process called hibernation, which is used in Skordos to prevent generation of useless predictions, is introduced and described here. Another technique is introduced and described which further assits in controlling the inequality reasoning by exploiting hibernation. This technique involves changing the structure in which values are combined. It uses hibernation as an early filter to reduce the number of interactions resulting from Kirchhoff’s current law from exponential to quadratic in the number of interacting variables.