Table 2 Comparison of Parameter Estimates (PE) between the Proposed Semiparametric Mixed-Effects Model (SPPLMEM) and the Fully Parametric Mixed-Effects Model (FPLMEM)

\({\alpha }_{1}\)  

55.29

1.58

(52.03, 58.09)

55.86

1.722

(52.28, 58.00)

\({\alpha }_{2}\)

 − 6.38

2.36

(− 11.01, − 1.80)

 − 7.58

2.17

(− 11.94, − 3.40)

\({\alpha }_{3}\)

 − 5.69

0.67

(− 7.00, − 4.32)

 − 6.25

0.67

(− 7.60, − 4.90)

\({\sigma }_{\epsilon }^{2}\)

60.19

3.03

(54.74, 66.61)

72.3

3.25

(66.14, 79.14)

DIC

10,290

10,430