Context-Aware Parameter Estimation for Forecast Models in the Energy Domain

Continuous balancing of energy demand and supply is a fundamental prerequisite for the stability and efficiency of energy grids. This balancing task requires accurate forecasts of future electricity consumption and production at any point in time. For this purpose, database systems need to be able to rapidly process forecasting queries and to provide accurate results in short time frames. However, time series from the electricity domain pose the challenge that measurements are constantly appended to the time series. Using a naive maintenance approach for such evolving time series would mean a re-estimation of the employed mathematical forecast model from scratch for each new measurement, which is very time consuming. We speed-up the forecast model maintenance by exploiting the particularities of electricity time series to reuse previously employed forecast models and their parameter combinations. These parameter combinations and information about the context in which they were valid are stored in a repository. We compare the current context with contexts from the repository to retrieve parameter combinations that were valid in similar contexts as starting points for further optimization. An evaluation shows that our approach improves the maintenance process especially for complex models by providing more accurate forecasts in less time than comparable estimation methods.

[1]  Minglu Li,et al.  Advanced Web and Network Technologies, and Applications , 2006 .

[2]  Žliobait . e,et al.  Learning under Concept Drift: an Overview , 2010 .

[3]  George E. P. Box,et al.  Time Series Analysis: Box/Time Series Analysis , 2008 .

[4]  John A. Nelder,et al.  A Simplex Method for Function Minimization , 1965, Comput. J..

[5]  James W. Taylor,et al.  Triple seasonal methods for short-term electricity demand forecasting , 2010, Eur. J. Oper. Res..

[6]  Indre Zliobaite,et al.  Learning under Concept Drift: an Overview , 2010, ArXiv.

[7]  C. D. Gelatt,et al.  Optimization by Simulated Annealing , 1983, Science.

[8]  Agnar Aamodt,et al.  Case-Based Reasoning: Foundational Issues, Methodological Variations, and System Approaches , 1994, AI Commun..

[9]  Jörg Becker,et al.  Towards more Reuse in Conceptual Modeling - A Combined Approach using Contexts , 2007, CAiSE Forum.

[10]  Donald J. Berndt,et al.  Using Dynamic Time Warping to Find Patterns in Time Series , 1994, KDD Workshop.

[11]  Simone Diniz Junqueira Barbosa,et al.  Using Analogy to Promote Conceptual Modeling Reuse , 2007, ISoLA.

[12]  Yukihiro Nakamura,et al.  Stock Price Prediction Using Prior Knowledge and Neural Networks , 1997, Intell. Syst. Account. Finance Manag..

[13]  Gwilym M. Jenkins,et al.  Time series analysis, forecasting and control , 1972 .

[14]  Peter R. Winters,et al.  Forecasting Sales by Exponentially Weighted Moving Averages , 1960 .

[15]  R. Ramanathan,et al.  Short-run forecasts of electricity loads and peaks , 1997 .

[16]  Hong Peng,et al.  XML and Knowledge Based Process Model Reuse and Management in Business Intelligence System , 2006, APWeb Workshops.

[17]  Shivnath Babu,et al.  Processing Forecasting Queries , 2007, VLDB.

[18]  Wolfgang Lehner,et al.  Indexing forecast models for matching and maintenance , 2010, IDEAS '10.

[19]  Chusak Limsakul,et al.  A Computing Model of Artificial Intelligent Approaches to Mid-term Load Forecasting: a state-of-the-art- survey for the researcher , 2010 .

[20]  Rob J. Hyndman,et al.  Another Look at Forecast Accuracy Metrics for Intermittent Demand , 2006 .

[21]  Gerhard Widmer,et al.  Learning in the Presence of Concept Drift and Hidden Contexts , 1996, Machine Learning.