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

Table 3

Matrix of the correlation coefficients of the input indicators (correlation matrix).

	1.000	0.227	−0.644	−0.464	0.127	−0.336	−0.095	0.480	0.433	−0.598	−0.061
	0.227	1.000	−0.542	0.052	0.587	−0.234	0.269	0.327	0.540	−0.273	−0.120
	−0.644	−0.542	1.000	0.307	−0.487	0.435	−0.027	−0.427	−0.403	0.742	0.248
	−0.464	0.052	0.307	1.000	0.591	0.707	0.914	0.168	−0.122	0.716	0.051
	0.127	0.587	−0.487	0.591	1.000	0.015	0.758	0.233	0.021	0.039	−0.139
	−0.336	−0.234	0.435	0.707	0.015	1.000	0.651	0.502	0.272	0.627	0.094
	−0.095	0.269	−0.027	0.914	0.758	0.651	1.000	0.474	0.159	0.489	0.008
	0.480	0.327	−0.427	0.168	0.233	0.502	0.474	1.000	0.873	−0.054	0.143
	0.433	0.540	−0.403	−0.122	0.021	0.272	0.159	0.873	1.000	−0.208	0.123
	−0.598	−0.273	0.742	0.716	0.039	0.627	0.489	−0.054	−0.208	1.000	0.587
	−0.061	−0.120	0.248	0.051	−0.139	0.094	0.008	0.143	0.123	0.587	1.000