Time series components (trend, seasonality, cycle, irregular), Stationarity concepts (weak vs. strict stationarity), Trend estimation (moving averages, polynomial fitting, LOESS), Seasonal decomposition (classical, ST...
Time series components (trend, seasonality, cycle, irregular), Stationarity concepts (weak vs. strict stationarity), Trend estimation (moving averages, polynomial fitting, LOESS), Seasonal decomposition (classical, STL - Seasonal-Trend decomposition using Loess), Autocorrelation (ACF) and partial autocorrelation (PACF) analysis, Differencing and transformations for stationarity.
ARIMA models (p,d,q parameters, stationarity/invertibility conditions), Box-Jenkins methodology, Model identification (ACF/PACF interpretation), Parameter estimation (MLE, least squares), Model diagnostics (Ljung-Box test, residual analysis), SARIMA for seasonal data, Seasonal differencing and Fourier terms.
Simple exponential smoothing, Holt's linear trend method, Holt-Winters seasonal method, ETS framework (error, trend, seasonal components), Optimal smoothing parameters (MLE optimization), State space representation, Kalman filter for parameter estimation, Dynamic linear models and interventions.
Feature engineering (lagged variables, rolling statistics, Fourier features), Tree-based methods (XGBoost/LightGBM with time series splits), LSTM/GRU networks for sequential forecasting, Transformer models (Temporal Fusion Transformer, Informer), Ensemble methods (statistical + ML hybrid models), Cross-validation strategies (purged, embargoed, walk-forward).
Multivariate time series (VAR, VEC models), Hierarchical forecasting (bottom-up, top-down, optimal reconciliation), Anomaly detection (isolation forest, autoencoders, statistical process control), Probabilistic forecasting (quantile regression, conformal prediction), Automated ML (AutoTS, sktime, Darts), Production deployment (MLOps for time series, concept drift detection).