Dynamic Network Updating Techniques For Diagnostic Reasoning
This work addresses diagnostic reasoning for domains where probabilities change over time, but it appears incremental as it builds on existing influence diagram and sensitivity analysis techniques.
The authors tackled the problem of diagnostic reasoning with time-varying probabilities by proposing DYNASTY, a system that constructs probabilistic networks using influence diagrams and dynamic updating algorithms, resulting in a method that differentiates diagnoses based on required actions and uses equivalence classes for sensitivity analysis.
A new probabilistic network construction system, DYNASTY, is proposed for diagnostic reasoning given variables whose probabilities change over time. Diagnostic reasoning is formulated as a sequential stochastic process, and is modeled using influence diagrams. Given a set O of observations, DYNASTY creates an influence diagram in order to devise the best action given O. Sensitivity analyses are conducted to determine if the best network has been created, given the uncertainty in network parameters and topology. DYNASTY uses an equivalence class approach to provide decision thresholds for the sensitivity analysis. This equivalence-class approach to diagnostic reasoning differentiates diagnoses only if the required actions are different. A set of network-topology updating algorithms are proposed for dynamically updating the network when necessary.