Prediction-Based Maintenance of Existing Bridges Using Neural Network and Sensitivity Analysis

Table 3

Scaled values of each influencing factor.

Factor	Original data range	After scaled
		Mean	Standard deviation
Elevation (m)	−0.3∼1,106	0.0909	0.1347
Bridge length (m)	2∼1,433	0.0444	0.0844
Bridge width (m)	0.7∼50	0.2129	0.1124
Years in service (years)	1∼84	0.3833	0.2008
Carbon dioxide (ppm)	348.86∼409.87	0.3933	0.2413
Chloride (kg/m^3)	0∼17.3	0.057	0.1376
Large-size vehicles rate (%)	0∼62.6	0.3076	0.1786
Traffic volume (daily)	0∼56,874	0.0946	0.1143
Rainfall (cm)	776∼1,491	0.3617	0.2268
Snowfall (cm)	12.0∼1,263.8	0.4493	0.2166
Highest temperature (°C)	16∼26	0.7025	0.1737
Lowest temperature (°C)	−11∼−3	0.5851	0.2361