TY - GEN
T1 - Detecting structural breaks in seasonal time series by regularized optimization
AU - Wang, Bing
AU - Sun, Jie
AU - Motter, Adilson E.
PY - 2013
Y1 - 2013
N2 - Real-world systems are often complex, dynamic, and nonlinear. Understanding the dynamics of a system from its observed time series is key to the prediction and control of the system's behavior. While most existing techniques tacitly assume some formof stationarity or continuity, abrupt changes, which are often due to external disturbances or sudden changes in the intrinsic dynamics, are common in time series. Structural breaks, which are time points atwhich the statistical patterns of a time series change, pose considerable challenges to data analysis.Without identification of such break points, the same dynamic rulewould be applied to thewhole period of observation, whereas false identification of structural breaks may lead to overfitting. In this paper, we cast the problem of decomposing a time series into its trend and seasonal components as an optimization problem. This problem is ill-posed due to the arbitrariness in the number of parameters.To overcome this difficulty, we propose the addition of a penalty function (i.e., a regularization term) that accounts for the number of parameters. Our approach simultaneously identifies seasonality and trend without the need of iterations, and allows the reliable detection of structural breaks. The method is applied to recorded data on fish populations and sea surface temperature, where it detects structural breaks that would have been neglected otherwise. This suggests that our method can lead to a general approach for the monitoring, prediction, and prevention of structural changes in real systems.
AB - Real-world systems are often complex, dynamic, and nonlinear. Understanding the dynamics of a system from its observed time series is key to the prediction and control of the system's behavior. While most existing techniques tacitly assume some formof stationarity or continuity, abrupt changes, which are often due to external disturbances or sudden changes in the intrinsic dynamics, are common in time series. Structural breaks, which are time points atwhich the statistical patterns of a time series change, pose considerable challenges to data analysis.Without identification of such break points, the same dynamic rulewould be applied to thewhole period of observation, whereas false identification of structural breaks may lead to overfitting. In this paper, we cast the problem of decomposing a time series into its trend and seasonal components as an optimization problem. This problem is ill-posed due to the arbitrariness in the number of parameters.To overcome this difficulty, we propose the addition of a penalty function (i.e., a regularization term) that accounts for the number of parameters. Our approach simultaneously identifies seasonality and trend without the need of iterations, and allows the reliable detection of structural breaks. The method is applied to recorded data on fish populations and sea surface temperature, where it detects structural breaks that would have been neglected otherwise. This suggests that our method can lead to a general approach for the monitoring, prediction, and prevention of structural changes in real systems.
UR - http://www.scopus.com/inward/record.url?scp=84892421169&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84892421169&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84892421169
SN - 9781138000865
T3 - Safety, Reliability, Risk and Life-Cycle Performance of Structures and Infrastructures - Proceedings of the 11th International Conference on Structural Safety and Reliability, ICOSSAR 2013
SP - 3621
EP - 3628
BT - Safety, Reliability, Risk and Life-Cycle Performance of Structures and Infrastructures - Proceedings of the 11th International Conference on Structural Safety and Reliability, ICOSSAR 2013
T2 - 11th International Conference on Structural Safety and Reliability, ICOSSAR 2013
Y2 - 16 June 2013 through 20 June 2013
ER -