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designed to algcr.aaa ths cooPutatlon req[Ired to flnd the best paraneter<br />
valuea.<br />
For thls studlt tjre der of PalaDaters to b€ oPtlilted was 9Da1l.<br />
urually one or t$o. rnd the Roranbfoclt tch€8e (1960) r,aB colsldered<br />
to be sultable. Thi6 scheDe is a oulti.varlata nethod vhtch valles all<br />
lraradeter€ together ln accoldance wi'th a Etlategy based on tbe slope of<br />
the reBponse surface.<br />
A coEpall,son of the parrDet€r value cDtaln€d ualnq the Rogenbrock betlroal<br />
elth those obtalned by falk anil NleDcz!"rowicz (1978) using a graphical.<br />
Dethod sboued that botlr rnetjroalB gave broailly slDlla! .esu1ts. gecause<br />
co@put6r optLDllallon r,aa dlolc convenie[t, th€ Rosor'tblocF llethoal t'as<br />
used fo! the !€l|alnaler of tfi€ 6tudy.<br />
3.2 Appllcati.ott of optl,olzatlon pethoal<br />
Ihe!€ le a choice betveen obtatntng the beEt parameter vaLue fot each<br />
61n91e €vent o! flndlng ao&a klnd of rglobal' value by optlnlztng on<br />
sevelal, events togeth€r, th€ toroe! has t}re advantage of enabllng<br />
any telatl,onahlps betwcen tboat' paraseter valuc and stolB<br />
chalacterlatlcs to be lnvestlgated but gulfels flon tie dfuadvantage<br />
that the values obtalned Day have er!o!3 ai,re to ttat! plobl€Es wlth<br />
indlvidual storE!. By cdLnlng oventE the va!16btL1ty of the estLDates<br />
of the pa4Eeter valu6(g) 1s leduc€d and a sDootll€r reBponse sulface LE<br />
obtalned.<br />
A cooperative stualy of the re8ults obtaln€al using both tyFes of<br />
appllcatLon ls glven l-n Sectlon 3.4.<br />
3.3 Obiectlt e functLons<br />
The uae of an autooatlc optlDlzatton nethod requlreg the uger to choose<br />
en objectlv€ functlon uhlch Deasures the goodness of, f1t. S1x allffelent<br />
functlons wete lnvestlgated for thi6 study;<br />
(i)<br />
lntegral Squrre E$or (ISE). Ittis 18 a velsion of the<br />
co@n least squ.res functLon but scaled t a direnslonless<br />
Deasur€ o! the fit.<br />
rsE ' {'6G;qj,/r-eo} x rooi {3.r}<br />
where Qo - obselved Cllscharge<br />
%<br />
= discharge pledicted by eodel<br />
auld the slDeation ls ove! the hytLogralfi at Intelvals<br />
equal to ti€ tlDe step.<br />
(i1) Blassed Inregral Squalc Error (BISE) silch ls an atteDDt<br />
to put rlore eetght on t}|e gooahess-of-flt neat the 1rj<br />
valu€.