2016年美赛F题山东大学O奖论文

ForofficeuseonlyT1________________T2________________T3________________T4________________TeamControlNumber46634ProblemChosenFForofficeuseonlyF1________________F2________________F3________________F4________________2016MCM/ICMSummarySheet(Yourteam'ssummaryshouldbeincludedasthefirstpageofyourelectronicsubmission.)Typeasummaryofyourresultsonthispage.Donotincludethenameofyourschool,advisor,orteammembersonthispage.ModelingtoRefugeesPoliciesSummaryWiththousandsofrefugeesmovingacrossEuropeandmorearrivingeachday,considerableattentionhasbeengiventorefugeeintegrationpoliciesandpracticesinmanycountriesandregions.Webuildaseriesofmodelstoexplorethefactorsinvolvedwithfacilitatingthemovementofrefugeesfromtheircountriesoforiginintosafehavencountries.Firstly,weoptimizetheControlVariablealgorithmtobuildamodeltoanalyzethemeasuresandparametersofthecrisis.Wesetfactorssuchasthepsychologicalqualityandfaithofrefugees,theresourcesandrefugeepolicyoftherefugee-receivingcountry,therefugees’saturationoftherefugee-receivingcountryandthenaturaldisasterorterrorist.Findingoutthateveryfactorisofcrucialimportance,andthemorefavorabletheconditionsare,themorelikelytherefugeesmovetothesafecountries.Secondly,weusetheindexsetabovetoanalyzetheflowofrefugees.FromtheoptimizedSmallWorldNetworkalgorithm,wefindthatthereare637000refugeesarrivingEUayear,amongthem,311000refugeeswilltransferviaEasternMediterranean,221000refugeesviaWestMediterranean,45000refugeesviaWestBalkans,32000refugeesviaEasternBorders,18000refugeesfromAlbaniatoGreece,and10000refugeesviaCentralMediterranean.Andthetransferrateshouldbecontrolledbelow50187permonth.Thirdly,weconsidertheparameterssetintask1aredynamic,findingoutthatourmodelisalsoapplicativewhileweshouldadjustthedetailsinourmodel.Finally,wemakeareporttodiscussourmodelindetailandraisetheneededpolicysupport.Weanalyzetheimpactofexogenouseventsaswell.Meanwhile,westatethescalabilityofourmodel.Thenwebelievethatourmodelcansolvemostoftheproblems.Intheend,weanalyzethestabilityandsensitivityofmodel.Wealsoconcludethestrengthsandweaknessesofourmodel.Further,theaccuracyofourmodelneedsimproving.Team#46634page1of22IntroductionBackgroundWithhundredsofthousandsofrefugeesmovingacrossEuropeandmorearrivingeachday,considerableattentionhasbeengiventorefugeeintegrationpoliciesandpracticesinmanycountriesandregions.Historyhasshownusthatmassfleeingofpopulationsoccurasaresultofmajorpoliticalandsocialunrestandwarfare.Thesecrisesbringasetofuniquechallengesthatmustbemanagedcarefullythrougheffectivepolicies.EventsintheMiddleEasthavecausedamassivesurgeofrefugeesemigratingfromtheMiddleEastintosafehavencountriesinEuropeandpartsofAsia,oftenmovingthroughtheMediterraneanandintocountriessuchasTurkey,Hungary,Germany,France,andUK.BytheendofOctober2015,Europeancountrieshadreceivedover715,000asylumapplicationsfromrefugees.Hungarytoppedthechartswithnearly1,450applicationsper100,000inhabitants,butwithonlyasmallpercentageofthoserequestsgranted(32%in2014),leavingclosetoathousandrefugeeshomelessperevery100Kresidentsofthecountry.Europehasestablishedaquotasystemthateachcountryhasagreedtotakeinaparticularnumberofrefugees,withthemajorityoftheresettlementburdenlyingwithFranceandGermany.OurWorkFirstly,weoptimizetheControlVariablealgorithmtobuildamodeltoanalyzethemeasuresandparametersofthecrisis.Wesetthepsychologicalqualityofrefugees,thefaithoftherefugees,thematerialandfinancialresourcesoftherefugee-receivingcountry,therefugeepolicyoftherefugee-receivingcountry,therefugeessaturationoftherefugee-receivingcountryandthenaturaldisaster,terroristasfactors,findingoutthateveryfactorisimportanttothecrisis,andthemorefavorabletheconditionsare,themorelikelytherefugeesmovetothesafecountries.Secondly,weusetheindexsetabovetoanalyzetheflowofrefugees.FromtheoptimizedSmallWorldNetworkalgorithm,wefindthatthereare637000refugeesarrivingEUayear,amongthem,311000refugeeswilltransferviaEasternMediterranean,221000refugeesviaWestMediterranean,45000refugeesviaWestBalkans,32000refugeesviaEasternBorders,18000refugeesfromAlbaniatoGreece,and10000refugeesviaCentralMediterranean.Andthetransferrateshouldbecontrolledbelow50187permonth.Thirdly,weconsidertheparameterssetintask1aredynamic,findingoutthatourmodelisalsoapplicablewhileweshouldadjustthedetailsinourmodel.Finally,wemakeareporttodiscussourmodelindetailandraisetheneededpolicysupport.Weanalyzetheimpactofexogenouseventsaswell.Meanwhile,westatethescalabilityofourmodel.Thenwebelievethatourmodelcansolvemostoftheproblems.AssumptionsIgnoretheslimrefugeescountry.Thecountriesthathavefewrefugeesorreceivefewrefugeesdonothavemuchinfluenceonourmodel.Ignorethetimeofpreparationfortransfer.Thetimeofpreparationfortransfercannotdetermineitssignificancecompletely,andwetakethetimeofpreparationfortransferintoconsiderationwhenwediscussthemutualreferenceofallwork.Team#46634page2of22Table1showsthedefinitionsofthesymbols.Table1SymboldefinitioninstructionSymbolMeaning1Fthesuccessrateofrefugeesarrivinginsafe-havencountries(1)1Frefugees’psychologicaldiathesisoftheirowndiathesis(2)1Frefu