Operational Efficiency Evaluation of Iron Ore Logistics at the Ports of Bohai Bay in China: Based on the PCA-DEA Model

Table 8

Negative-to-positive transform of the principal components of the input and output indicators.

Port sample	Principal components of the input indicators				Principal components of the output indicators
	Dalian	0.381	0.380	0.933	0.900	0.607	0.445
Yingkou	0.364	0.691	1.823	0.344	1.301	5.196
Tianjin	2.000	0.210	2.406	6.755	0.532	0.735
Rizhao	1.166	4.709	0.069	1.648	5.758	3.430
Tangshan	53.441	2.234	1.801	0.492	1.235	0.314
Qingdao	0.139	18.265	3.621	1.220	3.547	0.299
Yantai	0.415	0.095	0.541	0.484	0.094	1.826