简介:Thispaperpresentsanewapproachtosolvemixed-variableunitcommitment(UC)problemswithnon-smoothcostfunctionsbasedonageneralizedpatternsearchfilter(GPS-filter)algorithm.AGPS-filteralgorithmdoesnotrequireanyinformationaboutthegradientoftheobjectivefunctionwhilesearchingforanoptimumsolution.Atthesametime,itisavailableforsolvingmixed-variableoptimizationproblems,whichisverysuitableforUC.AnewsuitablediscreteneighborhoodstructurewithUCcharacteristicsisproposedtoimproveGPS-filterefficiently.Alotofmultipleunits'statesarefixedbeforesearch;hence,thepollingsearchofdiscretevariableisefficientforafewuncertainunits.Numericalexperimentsareincludedtodemonstratetheproposedapproach'sabilitytohandlethehighlynonlinear,discontinuous,non-smoothcostfunctionsandmixedvariablesoftheUCproblem.
简介:Thepaperstudieschannelchoicedecisionsinamulti-channelsupplychainunderastrategywherethereisanex-antecommitmentmadeontheretailpricemarkup.Themarketdemandisuncertainanddependentonthepriceandsalesefforts.Theresultsshowthatinanychannelstructure,whenmakingorderdecisionstheretaileronlyexaminesthepriceratioandthefluctuationsizeofrandomdemand,ratherthanthechannelcostandtheretailer’smarketingefficiency.Whentheretailpricerises,themanufactureriswillingtoincreaseinventoryquantityfordirectsales,becausethemanufacturer’sprofitmarginishigherindirectchannel.Theincreaseindemandfluctuationonlyaffectsthedegreeofchannelpreferencebutdoesn’tchangethemanufacturer’schannelchoice.Nomatterinwhichlevelthepriceratiois,whenthesalesefficiencyofretailchannelisnothighorthedemandproportionofdirectchannelislow,themanufacturerandtheretailerwillbebothapttochooseadual-channelstructure.Thenaddingadirectchannelbecomesamarketingstrategy,ratherthanacompetitoroftheretailchannel,andhelpsthesupplychainwinmoremarketdemand.