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Multi-Model Fusion for Robust Time-Series Forecasting. Weizhong Yan. Industrial Artificial Intelligence Lab GE Global Research Center Niskayuna, NY 12309. Outline. Problem Description Datasets Challenges and modeling strategies Our Approach The Results Final Remarks.
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Multi-Model Fusion for Robust Time-Series Forecasting Weizhong Yan Industrial Artificial Intelligence Lab GE Global Research Center Niskayuna, NY 12309 W. Yan
Outline • Problem Description • Datasets • Challenges and modeling strategies • Our Approach • The Results • Final Remarks W. Yan
Dataset characteristics Time series with seasonality, trend, and outlier Non-stationary W. Yan
Challenges and modeling strategies A large number of time series with different features. Manual, ad-hoc modeling strategies are not working A model-building strategy that can automatically identify features (i.e., trend, seasonality, etc) of time series and arrives in a forecast model with robust & accurate performance for a large number of time series W. Yan
Our Approach(1) - Preprocessing automatically Feature identification Feature treatment Outliers Trend W. Yan
Our Approach(2) - Modeling Generalized Regression NN W. Yan
Our Approach(3) - Why GRNN? It’s a variation of “nearest neighbor” approach Forecast for an input is a weighted average of the outputs in the training examples. The closer an input to the training example, the larger the weight of its corresponding output. • Advantages • It’s a universal approximator • It’s fast in training (one-pass learning) • It’s good for sparse data • Disadvantages • It requires large amount of online computation • It almost does not have any extrapolation capability (forecast is bounded by min & max of the observations) W. Yan
Results(1) W. Yan
Results(2) W. Yan
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Results(6) W. Yan
Final remarks • Developing a robust time series forecasting model is a challenging task. • Developing an automatic model building process that can be reliably applied to a large number of time series with varying features is even more challenging. • When the number of historical data points is small, fusion of multiple simple models seems to work better than a single complex model does Future work • Using more GRNNs • Optimally determining the tunable parameter, spread, for GRNNs • … W. Yan
Thank you W. Yan