Drawing on the ensemble principle validated by Huber and
Stuckenschmidt~\cite{ref12}, the hybrid forecast is:
\[
\hat{y}_t = \alpha \cdot \text{XGBoost}(X_t)
+ (1-\alpha) \cdot \text{LSTM}(X_{t-k:t})
\]
where $\hat{y}_t$ is predicted demand at period~$t$, $X_t$ the
contemporaneous feature vector, and $X_{t-k:t}$ the historical sequence
over $k=12$ preceding periods. The blending coefficient $\alpha=0.4$ was
selected by grid search on the validation fold.
Based on the ensemble approach established by Huber and Stuckenschmidt, we construct our hybrid forecast using the following formula:
\[
\hat{y}_t = \alpha \cdot \text{XGBoost}(X_t)
+ (1-\alpha) \cdot \text{LSTM}(X_{t-k:t})
\]
In this equation, $\hat{y}_t$ represents the forecasted demand for time period $t$, while $X_t$ denotes the feature vector for the current period. The term $X_{t-k:t}$ captures the historical data sequence spanning $k=12$ previous time periods. We determined the optimal blending parameter $\alpha=0.4$ through systematic grid search evaluation using our validation dataset.