Research Article

Binary Logistic Regression Modeling of Idle CO Emissions in Order to Estimate Predictors Influences in Old Vehicle Park

Table 4

Logistic estimates for CO emission test failure.

ModelPredictorsWald statistics (df)

SRBVA0.0770.01431.08 ()a1.080
EP()−0.7660.17319.580 ()a0.465
EP()−1.140.2915.453 ()b0.319
SFS()1.9380.58510.961 ()a6.944
K()2.9431.0427.969 ()b18.969

EUOR0.0000170.000001217.803 ()a1.000017
EP()−1.6360.157108.538 ()a0.195
EP()−2.3190.2493.342 ()a0.098
SFS()−7.1061.0545.829 ()a0.00082
K()4.5021.03119.067 ()a90.181

USAOR0.0000450.00000656.939 ()a1.000045
VA0.5970.07859.413 ()a1.822
EP()−6.4360.9843.167 ()a0.001603
EP()−8.5251.16653.485 ()a0.000199
SFS()9.51.36648.339 ()a1,3360.72
K()6.411.24626.483 ()a608.141

Notes: value ≤ 0.01; value ≤ 0.05; df: degree of freedom; EP(): first subcategory in category of engine power (41–70 kW); EP(): second subcategory in the category of engine power (>71 kW); SFS(): first subcategory in category of the system of fuel supply (vehicles with carburetor); K(): first subcategory in the category of the catalytic converter (CAT) (vehicles without CAT).