0.9 



1 1 



1 



»y 





1 ~^= — - 1 



■ 



- 



0.8 





1/ 











" 



0.7 





1/ 











" 



0.6 



- 













- 



0.5 



04 



0.3 



- NORMAL DISTRIBUTION^^^ f 

 CURVE ^~^W 













" 



0.2 



1 



J* 



■ T^ 1 | 







a 



LEGEND 

 OBSERVED DATA 

 USING t 



1 ' 





"" 



NORMALIZED PERCENT ERROR. _ 



Figure 11. Normal distribution curve for 5 model data 



P 



CONSERVATIVE TREND- 



OBSERVED DATA 



MODIFIED SURF PARAMETER. £ L 



Figure 12. Expected value and more conservative trend 

 curves for 5 model 

 L P 



20 



