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This work explores the application of Dynamic Bayesian Networks (DBNs) for detecting early signs of problems in various fields, including oil refineries and gene expression studies. By utilizing multivariate time series data, the study addresses challenges such as large variable numbers, short time series lengths, and changing dependencies. Innovative efficient learning algorithms and architectures are developed, enabling non-statisticians to integrate expert knowledge with data. The approaches involve intelligent operators and heuristic grouping algorithms to enhance DBN performance, paving the way for future research and clinical applications.
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Explaining Multivariate Time Series to Detect Early Problem Signs Architectures and Efficient Learning Algorithms for Dynamic Bayesian Networks Allan Tucker, Xiaohui Liu
Datasets • Visual Field & Gene Expression • Large/Huge number of variables • Short Multivariate Time Series • Longitudinal (Experimental Conditions / Patients) • Oil Refinery • Large Possible Time Lags • Changing Dependencies
Dynamic Bayesian Networks • Probabilistic Graphical Models • Easily Used by Non-Statisticians • Able to Combine Expert Knowledge with Data • Incorporate Hidden / Temporal Nodes etc.
Developing Specialist DBNs • Previously Used DBNs to Generate Explanations from Oil Refinery Data • Hidden Nodes to Model Changing Operating Modes • DBN Model to Combine Visual Field MTS Data with Non-MTS Clinical Data • Combining Gene Expression Experiments
Efficient Learning Algorithms • Heuristic Grouping Algorithms • Seeding Evolutionary Algorithms • Intelligent Operators • Time Lag Mutation Operators • DBN Link Crossover Operators • Spatial Crossover and Mutation (VF Data)
Sample of Publications A Tucker, S Swift and X Liu, "Variable Grouping in Multivariate Time Series via Correlation", IEEE Transactions on Systems, Man & Cybernetics: Part B: Cybernetics, 31:235-245, (2001). A Tucker, X Liu and A Ogden-Swift, “Evolutionary Learning of Dynamic Probabilistic Models with Large Time Lags”, International Journal of Intelligent Systems, 16:621-645, (2001). P Kellam, X Liu, N Martin, C Orengo, S Swift, A Tucker, “A Framework for Modelling Virus Gene Expression Data”, Intelligent Data Analysis – An International Journal, Vol. 6, No. 3, IOS Press, Netherlands, pp. 265-280, (2002).
The Future • Extend Work on DBNs for VF Data • Incorporate Expert Knowledge • Include more clinical information • Classify types of disease from MTS • Look into Modelling Continuous Variables • Gaussian Networks • Continuous BNs