Table 1.

Searching space of XGBoost model.

Parameters	Symbol	Search Space
Maximum tree depth	$D_{max}$	2, 4, 6, 8
Minimum child weight	$w_{mc}$	2, 3, 4, 5
Early stop round	e	100
Learning rate	$\tau$	0.1
Number of boost	N	60
Maximum delta step	$\delta$	0.4, 0.6, 0.8, 1
Subsample ratio	$r_s$	0.9, 0.95, 1
Column subsample ratio	$r_c$	0.9, 0.95, 1
Gamma	$\gamma$	0, 0.001