All Of Me 英文阅读材料(2600字)

发表于:2020.8.13来自:www.fanwen118.com字数:2600 手机看范文

All Of Me 予我所有 [Verse 1:]第一节: What would I do without your smart mouth 没有你伶牙俐齿我怎么办吶 Drawing me in, and you kicking me out 轻易的收我进来,又踹了我出去 Got my head spinning, no kidding, I can't pin you down 让我晕头转向,不是开玩笑,我真的无法定住你 What's going on in that beautiful mind 你美丽的思维里到底在考虑着什么 I'm on your magical mystery ride 我在你魔法秘境里兜兜转转 And I'm so dizzy, don't know what hit me, but I'll be alright 我还眩晕着,不知道什么击中了我,不过我想这没什么关系 [Bridge:]衔接: My head's under water But I'm breathing fine You're crazy and I'm out of my mind [Chorus:]合音: 'Cause all of me 因为所有的我 Loves all of you 都爱所有的你 Love your curves and all your edges 沉浸于你所有的曲线和背影 All your perfect imperfections 所有你完美的不完美 Give your all to me 把你的所有都交给我 I'll give my all to you 我把所有的自己都交给你 You're my end and my beginning 你是我的终点和我的起点 Even when I lose I'm winning 无论我的输赢 1 / 3

'Cause I give you all of me 因为我给了你所有的自己 And you give me all, all of you, oh 你给了我所有的你 [Verse 2:]第二节 How many times do I have to tell you 不知告诉你了多少次 Even when you're crying you're beautiful too 即便你在哭喊,你也是那么美丽 The world is beating you down, I'm around through every mood 无论这个世界负你几何,我都陪你一起度过 You're my downfall, you're my muse 你是我的奔涌而下的瀑布,你是我的缪斯 My worst distraction, my rhythm and blues 你拨乱了我每根神经,我所有的旋律和忧愁 I can't stop singing, it's ringing, in my head for you 我的歌声停不下来,它在召唤我,在我的脑海里为你召唤着我 [Bridge:] My head's under water 仿佛坠入水中 But I'm breathing fine 我还照常呼吸着 You're crazy and I'm out of my mind 你真是疯狂,我也只好陪你一起 [Chorus:]合音: 'Cause all of me 因为所有的我 Loves all of you 都爱所有的你 Love your curves and all your edges 沉浸于你所有的曲线和背影 All your perfect imperfections 所有你完美的不完美 Give your all to me 把你的所有都交给我 I'll give my all to you 2 / 3

我把所有的自己都交给你 You're my end and my beginning 你是我的终点和我的起点 Even when I lose I'm winning 无论我的输赢 'Cause I give you all of me 因为我给了你所有的自己 And you give me all, all of you, oh 你给了我所有的你 Give me all of you 把你自己交给我 Cards on the table, we're both showing hearts 知根知底,心有灵犀 Risking it all, though it's hard 赌上所有,即便它那么难下决心 [Chorus:]合音: 'Cause all of me 因为所有的我 Loves all of you 都爱所有的你 Love your curves and all your edges 沉浸于你所有的曲线和背影 All your perfect imperfections 所有你完美的不完美 Give your all to me 把你的所有都交给我 I'll give my all to you 我把所有的自己都交给你 You're my end and my beginning 你是我的终点和我的起点 Even when I lose I'm winning 无论我的输赢 'Cause I give you all of me 因为我给了你所有的自己 And you give me all, all of you, oh 你给了我所有的你 3 / 3




第二篇:电子商务英文阅读材料 46700字

Auctioningsupplycontractswithuncertaindemand

CuihongLi

GraduateSchoolofIndustrialAdministration

CarnegieMellonUniversity

5000ForbesAvenue

Pittsburgh,PA15213

cuihong@andrew.cmu.edu

AlanScheller-Wolf

GraduateSchoolofIndustrialAdministration

CarnegieMellonUniversity

5000ForbesAvenue

awolf@andrew.cmu.eduAnupriyaAnkolekarSchoolofComputerScienceCarnegieMellonUniverity5000ForbesAvenuePittsburgh,PA15213anupriya@cs.cmu.eduKatiaSycaraRoboticsInstituteCarnegieMellonUniversity5000ForbesAvenuePittsburgh,PA15213

katia@cs.cmu.edu

Abstract

Designofthecontractform,togetherwiththenegotiationmechanismandstrategy,comprisethecoredecisionsinane-contractingprocess.Inabusiness-to-businessscenarioabuyer(e.g.,aretailer)usuallyneedstosignacontractwithasupplier(e.g.,aman-ufacturer)tosatisfyademandthatisuncertainatthetimeofcontracting.Thebuyerwouldliketohaveordering?exibilitytorespondtotheuncertaindemandrealization.Butthesupplythatcanbeprovidedmaybeconstrainedbythecapacityinvestmentofthesupplier,whichhastobemadeinadvance.Thecapacityofasuppliermayei-therbeobservableandhencecontractable,orunobservableandhencenotenforcablebyacontract.Weproposetwocontractforms,anoptioncontractforthesituationwithobservablecapacity,andawholesalepricecontractwithafranchisefee(WF)forthesituationwithunobservablecapacity.Inbothcontractsthebuyerplacesher?nalorderafterthedemandisknown.Inanoptioncontractthebuyer?rstpaysapremiumfeeforreservingacertaincapacityfromthesupplierinadvance,andthenanexercisefeeforeachunitthatisordered.InaWFcontractthesupplierchargesawholesalepriceforeachunitorderedbythebuyer,butpaysa?xedfranchisefeetothebuyer.Wepresentoptimalauctionmechanismsindi?erentprotocolsforthebuyertonegotiateanoptioncontractoraWFcontractwithcompetingsuppliers.Bothcontractsgeneratehigherutil-ityforthebuyerthanthecontractinwhichthebuyerprocuresinadvance.Ourresultsshowthattheoptimalauctionsforthesetwocontractshavethesameoutcome.Wealsodiscusstheimplementationofe-contractingbasedonourcontractauctionmechanismswithsoftwareagenttechnologies.

1

1Introduction

Therapiddevelopmentofcomputerandcommunicationtechnologieshasacceleratedthebusinessprocessesfromlaborservicestoelectronic(semi-)automatedprocesses[13].Con-tractingisoneoftheimportantbusinessprocessesthathasrecentlyreceivedmuchattentioninthistrendtowardelectronictransactions.E-contractingaimstoautomatetheprocessofcreating,negotiating,closingandmonitoringtheperformanceofcontracts[2].Theproperdesignofthecontract,andthenegotiationmechanismandstrategy,dependsonthespeci?cbusinesssituation,andisthecoreofthedecisionsinthee-contractingprocess.

Contractinginabusiness-to-consumer(B2C)andinabusiness-to-business(B2B)scenarioaredi?erent.InaB2Cscenario,forexampleoftheauctionsoneBay,theitemstoexchangeareprede?nedinthequantityandotherattributes.Acontractusuallyonlyneedstospecifyaone-shotexchangecondition,forexample,theprice.Astandardcontractformcanthusexist,andthenegotiationissimple,becausetherearefewattributes,usuallyonlytheprice,tonegotiate.Butinabusiness-to-business(B2B)worldthecontractingpartiesareusuallyinvolvedinarelationshipoveranextendedhorizon.Theservice/goodtonegotiateandcontractmaybecon?gurable,andhencethecontractcanbehighlyunstructuredandinvolvemanyattributes,suchastheprice,deliverytime,quantity,etc.ThisnegotiationismorecomplicatedthaninaB2Cscenariobecausemultipleattributesareinvolved,andsometimeseventhecontractformcanbeanobjectofnegotiation.Moreover,thegoalofB2Bcontractingisnotonlytoensureaproperdivisionofpro?ts,butalsotocreatemorepro?t,bycoordinatingandenforcingthebehaviorsofbothparties.DesignofthecontractformandnegotiationmechanismisthusespeciallyimportantinaB2Bscenario,toachievecoordinationandane?cientwin-winsituationforbothparties.

Considerabuyer(retailer)thatwantstosignacontractwithasupplier(manufacturer)tosatisfythedemandinacomingsellingseason.Thebuyermaynotknowtheexactdemandintheseasonwhenshesignsthecontract,asshehastocontractwithasupplierwellinadvancesothatthelatterpartycanprepare,forexample,byprocuringcomponentsandrawmaterialsfromherupstreamsupplier.Thiscapacityset-upmayrequirelongleadtime,leavingnoopportunityforthesuppliertoexpandthecapacityduringtheseason:thecapacityinvestmentofthesupplierconstrainsthesupply.Butwhilethesupplierdoesnotwanttowastemoneyonexcesscapacity,thebuyerdoesnotwantcapacityshortages.Toensureagooddemandsatisfactionlevelthebuyerthushastoprovideincentivesforthesuppliertoinvestinsu?cientcapacity.Therearedi?erentwaystoprovidethisincentive.Onestraightforwardwayisforthebuyerto?xthequantitythatsheisgoingtobuy.Thisisequivalenttomakingadvancedprocurement,leavingnoordering?exibilitytocounterthedemanduncertainty.Anotherwaytoprovideincentivesforcapacityinvestment,whileretainingordering?exibility,istocompletetheprocurementintwostages.Inthe?rststagethebuyerreservescapacityandinthesecondstagethebuyerpurchasestheproductbasedontherealizeddemand.Thisprocesscanberegulatedbyanoptioncontract.Withanoptioncontractthebuyerpaysthesupplierapremiumfeefortherighttobuyacertainamountoftheproduct.Afterthe

2

demandisobserved,thebuyercanplaceordersfortheproductinanamountuptothenumberofoptions,payinganexercisefeeforeachunitthatisordered.Anoptioncontractallowsrisksharing,andhenceinducesbettercoordination,creatingawin-winsituationbetweentheparties.Thebuyerwillordermoreonaveragethanshewouldunderacontractinwhichshehastoperformalltheprocurementbeforethedemandisknown,andthesupplierwillinvestmoreincapacitythanshewouldwithoutcontractinguponcapacityreservation.

Withanoptioncontractthebuyermustbeabletoobserveandverifythecapacitypreparedbythesupplier.Ifthecapacityisnotobservable,thecapacityreservationcannotregulatethecapacityinvestmentofthesupplier.Inthissituationtheincentiveforcapacityinvestmentonlyreliesontheexercisefee,whichisequivalenttoawholesaleprice.Inthiscasepayingapremiumfeemakesnosense,insteadafranchisefee,paidbythesupplier,thatisindependentoftheorderedquantitycanensurebetterpro?tdistributionbetweenthetwoparties.Wecallthiscontractawholesalepricecontractwithafranchisefee(WF).

Typicallyabuyerdoesnotknowthee?ciency,ortheproductioncost,ofasupplier.Whenseveralsuppliersarepossiblecandidatestoprovidetheproduct,competitivebiddingisane?cientmechanismforthebuyertodiscoverthemostcompetentsupplierandnegotiateacontract.Thismaytakeplaceinamulti-attributeauctionthatinvolvesallthenegotiabletermsinthecontract,forexamplethepremiumfee,exercisefeeandcapacityinanoptioncontract,andthewholesalepriceandthefranchisefeeinaWFcontract.Therearetwomainclassesofprotocolsforsuchmulti-attributeauctions:The?rstclassisauctionswithamenuofcontracts,andthesecondclassisauctionswithascoringrule.Inthe?rstclasstheauctioneer,thebuyer,announcesasetofcontractalongwiththepreferenceorderbetweenthecontracts.Thesuppliersbidbychoosingacontract,andtheonewhobidsthehighestrankedcontractisthewinner.Inthesecondclasstheauctioneerannouncesascoringfunction.Thesuppliersbidbysubmittingcontracts,andthewinnerisdecidedbythescoringrule.

Inthispaperwepresentoptimalauctionmechanismsindi?erentprotocolsforbothanoptioncontractandaWFcontract,whenthecostofasupplierisunknowntothebuyer.Wealsodiscusstheimplementationandautomationofthecontractauctionmechanismswithsoftwareagenttechnologies.Althoughonewouldexpectthebuyertolosecertainadvantageswhenasupplier’scapacityisunobservable,surprisinglyweshowthatbyappropriatelydesigningthecontractformandauctionmechanism,thebuyercanactuallyachievethesameoptimalexpectedutilitywithunobservablecapacityaswithobservablecapacity.Inbothsituations,theordering?exibilityinanoptioncontractoraWFcontractresultsinhigherutilityforthebuyerthanpre-specifyinga?xedorderingquantity.

Therestofthepaperisorganizedasfollows:WereviewtherelatedworkinSection2.Section3setsuptheproblem,andprovidestheframeworkforauctionmechanismdesign.WepresenttheoptimalauctionmechanismsforanoptioncontractinSection4,andforaWFcontractinSection5.TheimplementationandautomationofthesupplycontractauctionswithsoftwareagentsisdiscussedinSection6.

3

2Relatedwork

Insupplychainmanagementdesignofcontractshasbeenanactivesubjectaimedatreconcil-ingcon?ictsandachievebettercoordinationbetweenparties:[3]providesagoodintroductionandsurveyonthiswork.Itprovidestheanalysisoftheoptimaloptioncontractandwholesalepricecontract(withoutafranchisefee)betweenabuyerandasupplierwhenthedemandforecastisprivateinformationofthebuyer,butthecostofthesupplierisknownbythebuyer.Thewholesalepricecontractresultsinlesspro?tforthebuyerwhencapacityisun-observable,ascomparedtotheoptioncontractwhencapacityisobservable.Inourpaperwestudyauctionsforsupplycontractswhentherearemultiplecompetingsuppliersandthecostsofsuppliersareunknown.Thewholesalepricecontract,byintroducingafranchisefee,actuallyresultsinthesameoptimaloutcomeasanoptioncontract.Anotherrelatedwork,

[7],investigatestheroleofoptionsinabuyer-suppliersystem,illustratinghowtheyprovide?exibilityandachievechannelcoordination.Thatworkisbasedoncompleteinformation-eachpartyknowstheother’scostorrevenue.

Auctionshavebeenconsideredinprocurementtodiscoverthemostcompetentsupplier,thuscuttingcost.Theauctionmechanismforabuyertoprocurefromoneofmultiplecompetingsuppliersisstudiedin[6]and[5].Theitemtoauctionisasupplycontractwithtwoattributes:theproductquantityandpayment.Inourpaperwestudytheauctiondesignforasupplycontractinwhichtheorderingquantityisnotspeci?edbutdeterminedafterwards,basedontherealizeddemand.Undersuchdemanduncertaintythebuyerachieveshigherpro?twithanoptioncontractoraWFcontractthaninacontractwithapre-speci?edquantity.Indirectmulti-attributeauctionmechanismsarestudiedin[4],whichproposesascoringrulebasedonwhich?rst-scoreandsecond-scoresealed-bidauctionsimplementtheoptimalauctionmechanism.Thetwoattributesinthispaperarethepriceandquality(whichcanalsobeinterpretedasthequantity).Thedesignofthescoringruleinourpaperisinspiredby[4],butourauctionsarebasedondi?erentcontracts,usinganEnglishauctionprotocol.Englishauctiondesignformulti-attributeitemsisconsideredin[9,8,10].Theutilityfunctionofthebuyerandthescoringrulearebothlinearfunctionsoftheattributes.Basedonthislinearfunctionalformtheoptimalweightsoftheattributesinthescoringruleareproposed,andthestrategiesofthebiddersareanalyzed.ThemechanismisonlyoptimalamongEnglishauctionswithlinearscoringfunctions,notwithgeneralscoringfunctionsasweallow.

Inrecentyearstherehasbeengrowingresearchinterestindesigningandimplementingau-tomatedelectronictradingsystemswithsoftwareagents.TheTradingAgentCompetition(TAC)inSupplyChainManagement[1]promotesandencouragesthedevelopmentofintelli-gentsoftwareagentscapableofbuyingorsellingproducts/materialsonbehalfofacompany.ThecompetitionisbasedonaB2Bsituation,andtheinternaloperationsofthecompaniesareintegratedintobiddingdecisions[17].Theseexchangesarebasedonaone-shotrela-tionship:thecontractsspecifytheorderingquantitiesandleavenopurchasing?exibilitytocounterdemanduncertainty.Finally,[20]studiesauctionmechanismdesignforsupplychainformationtoachieveglobale?ciency.Againtheauctionsarebasedonknowndemand.

4

3De?nitionofthemodel

Inthissectionweshall?rstdescribethenotationsandtheproblemsetting,thenintroducetheauctionmechanismdesignframework.Thebuyerhasuncertaindemanddofaproductˉ(·)=1?H(·)withprobabilitydistributionanddensityfunctionsG(d)andg(d).De?neH

forageneralprobabilitydistributionfunctionH(·).Thebuyersourcestheproductfromasupplierwithasupplycontract.Thelead-timeforproductioniszero.Butbeforeproduction(andaftercontracting)thesupplierhastoinvestincapacity,whichconstrainstheamountofsupply.Whenthecapacityisx,theexpectedsatis?eddemandisS(x),whereS(x)=ˉ(x).Ex[min{d,x}]=x?E[(x?d)+]withthederivativeS??(x)=G

Thebuyersellstheproducttoconsumersata?xedmarketpricerthatisexogenouslygiven.Therearensupplierswhocompeteforthesupplycontract.Eachsupplier’scostfunctioniscomposedoftwoparts:thecapacityinvestmentcostandtheproductioncost.Foreachunitofcapacity,whichproducesoneproduct,thecostkis?xedandidenticalforallsuppliers.Thecostisknownbythebuyerandthesuppliers.Theunitproduction

ˉ]dependsonasupplier’se?ciencyandisprivateinformationofthesupplier.costc∈[c

Followingthetraditionineconomicstheunitproductioncostisalsocalledthetypeofasupplier.Withinthepriorknowledgeofthebuyer,theproductioncostofeachsupplierfollowsanindependentandidenticalprobabilitydistributionF(c),withthedensityfunctionf(c).Theprobabilitydensityoftheminimumtypeamongthensuppliersisdenotedbyf(1)(c)=n(1?F(c))n?1f(c).WeassumethatF(c)/f(c)isanon-decreasingfunctionofc1.LetJ(c)=c+F(c)/f(c):J(c)iscalledthevirtualtypeofasupplier.Inadditionweassumethattherevenuerisbigenoughsothatr?J(ˉc)≥k.2

Generallyanauctionmechanism(B,κ,μ)hasthefollowingcomponents:asetofpossiblemessages(or“bids”)Biforeachbidderithatspeci?esthebiddingrule;awinnerdetermi-nationrule(or“allocationrule”)κ:B→PthatdeterminestheprobabilityPithatabidderiwillwinacontract,basedonthemessagesbsubmittedbyallbidders;acontractingruleμspeci?es,againasafunctionofallthemessagesb,thecontractμi(b)∈Tthatwillbeawardedtoeachbidderi[12].Anoptimalauctionmechanismisanauctionmechanismthatbringsthebestexpectedutilitytothebuyeramongallauctionmechanisms.Amechanismisindividuallyrational(IR)iftheexpectedutilityofaplayerinthismechanismisnon-negative.IRisanecessarypropertytoensurevoluntaryparticipation:onecannotforceaplayertoparticipateinthegameandacceptadealthatisworsethantheplayercouldgetoutside.Aswedonotassumeanyrestrictionsonthepossiblemessagesorthebiddingrules,thespaceofmechanismscouldbeenormouslylarge.OnespecialandsimpleclassofmechanismsareManyprobabilitydistributionssuchastheBetadistribution,whichhastheuniformdistributionasaspecialcase,satisfythiscondition.Pleasereferto[16]foranextensivediscussiononthosedistributions2Thisconditionensuresthatitispro?tableforthebuyertocontractwitheventheleaste?cienttypeofasupplier,asisshowninSection4and5.Withoutthisassumption,de?nec?suchatr?J(?c)=k.Thenthebuyerwillonlycontractwithasupplierwithc≤c?.Orequivalentlywecantreatc?astheupperboundcˉofasupplier’stype.1

5

calleddirectmechanisms.Inadirectmechanismeachbidderisaskedtodirectlyreporthertype,whichistheunitproductioncostinoursituation.Inotherwords,themessagespaceisthesameasthetypespaceinadirectrevelationmechanism.Adirectmechanism(L,M)consistsofapairoffunctions:L:[,ˉc]n→PandM:[ˉc]n→T,whereLi(c)istheprobabilitythatiwillwinacontractandMi(c)isthecontractawardedtoi[12],shouldibeoftypec.Amechanismisincentivecompatible(IC)ifitisthebeststrategyforabiddertotruthfullyrevealherprivateinformation:ICimpliesthattheexpectedutilityofasupplierismaximizedbytruthfulbidding,ortruthfulbiddingconstitutesaBayes-Nashequilibrium[11].InadirectICmechanism,eachbidderwillreporthertruetype.

Basedontherevelationprinciple,givenamechanismandanequilibriumforthatmechanism,thereexistsadirectmechanisminwhichitisanequilibriumforeachbiddertoreporthertypetruthfully,andtheoutcomeisthesameasinthegivenequilibriumoftheoriginalmechanism[12].TherevelationprincipleimpliesthattheoptimalmechanismamongdirectICmechanismsisalsooptimalamongallmechanisms.Despitethisfact,directICmechanismsarerarelyusedinpracticebecausetheyusuallyconsistofcomplexandun-intuitivewinnerdeterminationrulesandcontractingrules,sacri?cingtheadvantagesofasimplebiddingruleandbiddingstrategy.Buttheoutcomeofanoptimaldirectrevelationmechanismtellsthebestresultthatthebuyercanachieveinallpossiblemechanisms.

Inanauctionwithamenuofcontracts,thebuyerannouncesamenuofcontractsandeachsupplierbidsbyselectingonecontract.Thebuyerselectsthewinnerasthesupplierwhobidsthehighestrankedcontract,andthewinnerisawardedthatcontract3.

Inanauctionwithascoringrulethesuppliersaretheoneswhoproposecontracts,whichareevaluatedbythebuyerbasedonthescoringrule.Anauctionwithascoringrulecanbeaone-shotauction,inwhicheachsuppliersubmitsacontractonceinasealedbid,afterwhichthewinnerisselectedandthecontractisdecidedbasedonthebids;oritcanbeadynamicauction,inwhichsupplierscanupdatetheirbidsbasedonthecurrentbiddinginformation.AnEnglishauctionisonesuchdynamicauctionprotocolcommonlypracticed.WewillconsiderareverseEnglishauction,inwhichthesellers,seekingacontractwiththebuyer,startwithhigh“prices”anddecreasetheirbidssequentially.WepresentanoptimalauctionwithascoringruleinanEnglishauctionprotocol.Thesamescoringfunctioncanbeusedina?rst-scoreorsecond-scoresealed-bidauction,whichwillresultinthesameoptimaloutcomewithdi?erentbiddingstrategies.4InanEnglishauctionwithascoringrule,thebuyerannouncesascoringruleasafunctionofthenegotiableattributes,andthesuppliersbidbyeachsubmittingacontract.Theprovisionalwinneristhesupplierwhobidsthecontractwiththehighestscore,andthesupplieristentativelyawardedthecontractthatshe

Iftherearemorethanonesupplierwhobidthesamehighestrankedcontract,thetieisbrokenrandomlywithevenprobabilities.

4Thecounterpartsof?rst-priceandsecond-pricesealed-bidauctionsinamulti-attributeworldcanbecalled?rst-scoreandsecond-scoresealed-bidauctions.Inboththeseauctionsthebidderwiththehighestscoredbidwinstheauction.Inthe?rst-scoresealed-bidauctionthewinnerisawardedthecontractthatshebids.Inthesecond-scoresealed-bidauctionthewinnercanchooseanycontractthathasthesamescoreasthesecondhighestscoresubmittedbythebidders.3

6

bid5.Informedofthewinningcontractandscore,ineachroundtheothersupplierswhoarenotthewinnermayupdatetheirbidstooutbidthecurrentwinningcontractwithrespecttothescore6.Thesupplierswhocannotincreasetheirscoresquittheauctionandwillnotparticipateintherestofthebiddingprocess.Ifallsuppliers,excepttheprovisionalwinner,havequit,thentheauctionendsandtheprovisionalwinnerisawardedthewinningcontract.InSections4and5wepresentoptimalauctionmechanismsforaoptioncontractandawholesalepricecontractwithafranchisefee.We?rstderivetheoptimaldirectmechanismasabenchmarktoobtaintheoptimaloutcomethatthebuyercanachieveamongallauctionmechanisms(Section4.1and5.1).Thenweshowhowtheoptimaloutcomecanbeachievedwithanauctionwithamenuofcontracts(Section4.2and5.2)andanauctionwithascoringrule(Section4.3and5.3).

4Auctionsforanoptioncontract

Anoptioncontracthasthreeessentialnegotiableterms:theoptionquantityQO,theoptionpricewoandtheexercisepricewe.TheoptionquantityQOspeci?esthenumberofunitsofthecapacitythatthebuyerwantsthesuppliertopreparebeforetheseason,equivalentlythemaximumnumberofproductunitsthatthebuyercanorder.Foreachunitofcapacity(option),thebuyerpaysthesuppliertheoptionpricewo.Afterobservingthedemand,thebuyerplacesordersfortheproductduringtheseason.Foreachproductunitthatisordered,thebuyeradditionallypaystheexercisepricewe.RecallthatS(QO)isequaltotheexpectedsalesgivenacapacityofQO.

Givenanoptioncontract(wo,we,QO),theutilityofabuyerisequaltotheexpectedrevenue

b(w,w,Q)=(r?w)S(Q)?wQ,andtheutilityofasupplierisequalminusthefees:πOoeeoOOO

totheexpectedtotalpaymentfromthebuyerminusthecostonthecapacityandproduction,

s(c,w,w,Q)=(w?c)S(Q)?(k?w)Q.whichisrelatedtothesupplier’stypec:πOeeoOOOO

4.1Theoptimaldirectmechanism

Inanoptimaldirectmechanisminwhichthereisasinglewinner,themoste?cientsupplier,orthelowestc,mustbeawardedacontract.Otherwisethebuyercouldalwaysselectamoree?cientsupplierandbothcouldachievehigherpro?t.ThereforeanoptimaldirectmechanismisequivalenttodesigningacontractTO(c)=(wo(c),we(c),QO(c))foreachtypec.Atthebeginningoftheauctionthebuyerannouncesthecontractassociatedwitheachreportedtype,thenthesuppliersbidtheirtypes.Thesupplierwhobidsthelowesttypeisselectedasthewinnerandawardedthecontractcorrespondingtothereportedtype.Based

Againiftherearemorethanonesupplierwhobidthesamecontract,thetieisbrokenrandomlywithequalprobabilities.

6Toensuretheauctionterminatesin?nitetime,usuallyabidderisrequiredtoincreasethescoreofherbidbyanincrementnolessthanaspeci?edminimum.5

7

ontherevelationprinciple,wecanrestrictourmechanismstoICmechanisms,andstilldesignanoptimaldirectmechanism.

s(c??,c)betheutilityofasupplierwithtypecwhenshereportsthetypec??andthusLetπOs(c??,c)=[(w(c??)?c)S(Q(c??))+(w(c??)?choosesatypec??contractfromthebuyer.πOeoO????n?1ssk)QO(c)](1?F(c)).Letπ(c)=π(c,c),givenourmodeloftheprobabilitydistributionofsuppliers’types.Lemma4.1givestheconditionforamechanismbeingIC:

Lemma4.1Adirectmechanismisincentivecompatibleifandonlyif

(1)Theexpectedutilityofasuppliersatis?esthat

sπO(c)=u0+??ccˉS(QO(ρ))(1?F(ρ))n?1dρ(1)

whereu0isaconstant.

(2)QO(c)isanon-increasingfunctionofc.

Equation(1)impliesthatπs(ˉc)=u0,andπs(c??)≥πs(c)forc??≤c.Theconstantu0doesnotin?uencethechoiceofasupplier,wecanthushaveu0=0tomaximizethebuyer’sutility(ortominimizeasupplier’sutilitywiththesamecapacityinvestment)whilesatisfyingIR.??cˉˉ??csBasedonLemma4.1,theexpectedutilityofthewinningsupplierisπˉ=ccS(Q(ρ))(1?F(ρ))n?1dρf(1)(c)dc,whichcanbereformed,byinterchangingtheorderofintegration,as

πˉ=s??

ccˉS(QO(c))

??F(c)f(c)dc.f(c)(1)ˉThentheexpectedutilityofthebuyer,πˉb=cc[(r?c)S(Q(c))?kQ(c)]f(1)(c)dc?πˉs,isequal

to??cˉbπˉ=[(r?J(c))S(QO(c))?kQO(c)]f(1)(c)dc.c

Maximizingthebuyer’sexpectedutilityleadstoanoptimaldirectmechanism:

Proposition4.2Inanoptimaldirectmechanism,thenumberofoptionsintheoptioncon-tractis

ˉ?1(QO(c)=Gk),r?J(c)(2)

andtheoptionpricewo(c)andexercisepricewe(c)satisfy

??cˉ

Wo(c)+We(c)=cS(QO(ρ))(1?F(ρ))n?1dρ+cS(QO(c))+kQO(c),(1?F(c))(3)whereWo(c)=wo(c)QO(c)isthetotalpremiumfee,andWe(c)=we(c)S(QO(c))isthetotalexpectedexercisefee.

8

Wecannowcharacterizetheoptimaloutcomeofanoptioncontractauction:

1.Themoste?cientsupplieristhewinner,i.e.,theprobabilitythatthewinnerhasatypecisequaltof(1)(c)=n(1?F(c))n?1f(c).

2.Thecapacityinvestmentofthewinner,shouldshebeoftypec,isequaltoQO(c)=ˉ?1(k/(r?J(c))).G

3.Theexpectedutilityofthebuyerisequaltoπˉb=??cˉ

c[(r?J(c))S(QO(c))?kQO(c)]f(1)(c)dc.

??cˉ

c4.Theexpectedutilityofasupplierisequaltoπˉs(c)=S(QO(ρ))(1?F(ρ))n?1dρ.

Wecancomparethisoutcomewiththeoutcomeofanadvanced-purchasecontractauction.Anadvanced-purchasecontractspeci?esadeterministicnumberofproductunitsthatthebuyerordersfromthesupplier,alongwiththepaymentfromthebuyerfortheorder.Thusthistypeofcontracthasno?exibility.Suchacomparisonbetweenthebuyer’sexpectedutilitiesinbothcontractauctionsisprovidedinAppendix.Itshowsthatthebuyerachieveshigherexpectedutilitybyauctioninganoptioncontractascomparedtoanadvanced-purchasecontract.Anymechanismthatresultsinthesameoutcomeasdescribedaboveisanoptimalmechanism.Wenowusethisfacttoshowournexttwoauctionmechanismsareoptimal.

4.2Optimalauctionwithamenuofcontracts

Inanauctionwithamenuofcontracts,thedesignofthemenu,basedontheexpectationofthebiddingstrategiesofsuppliers,isthekeydecisionofthebuyer.Themenuofcontractscanberegardedascontractcustomizationfordi?erenttypesofsuppliers.Di?erenttypesofsupplierstradeo?thecapacityandpaymentdi?erently.Byo?eringdi?erentcombinationsofthenumberofoptionsandthepayment,thebuyerisabletocustomizethedesignofthecontractswithrespecttothesupplier’stype.Thisallowshertoextractmorepro?tfromthesystemwhenusingamoree?cientsupplier.Intheoptimaldirectmechanismwehavedesignedacontract(wo(c),we(c),QO(c))foreachtypecofasupplier.Givenamenuofthesecontracts,theauctionisoptimalifeachsupplierwillchoosethecontractdesignedforhertypebasedonthebiddingstrategytomaximizeherownexpectedutility.Proposition4.3establishesthatthecontractsintheoptimaldirectmechanismcomposeanoptimalmenuofcontracts.

Proposition4.3GivenamenuofcontractsTOwhereTO(c)=(wo(c),we(c),QO(c))satis-?esEquations(2)and(3),itisaBayes-NashequilibriumstrategyforasupplierctobidthecontractTO(c).TheauctionwiththemenuofcontractsTOresultsintheoptimaloutcome.

9

4.3Optimalauctionwithascoringrule

Inthisprotocolsuppliersbidcontracts,whichareevaluatedwithascoringrule.Letthescoreofacontractbid(wo,we,QO)bedenotedbysO(wo,we,QO).Areasonablescoringrulewillattachahigherscoretoacontractwithlowerpaymentorhighercapacity(optionquantity).Ifthevalueofthecapacitycanbemeasuredwithmonetaryvaluesindependentofthepayment,thenthescoringrulecanbeexpressedasaquasi-linearfunction:sO(wo,we,QO)=uO(QO)?(weS(QO)+woQO),whereuO(QO)isafunctionthatevaluatesthecapacityQOinmonetaryvalue,andweS(QO)+woQOistheexpectedpayment.Withsuchaquasi-linearscoringruletheoptionquantitythatasupplierwillbiddoesnotdependonthescore,butonlythescoringruleandthesupplier’stype[4].

Lemma4.4TheoptimalquantityQO(c)intheoptimalbidofasupplierwithtypecsatis?esdˉuO(QO)=cG(QO)+k.

OnemightthinkthatthebuyercouldsimplydesignthescoringruleaccordingtoherutilityfunctionandletuO(QO)=rS(QO).Thiswouldworkifthepro?tofatypeisindependentofthecapacitydecisionofothertypes,whichisthesituationwhenthebuyerhascompleteinformation.Butifthetypeisprivateinformationofasupplier,thecapacitydecisionofonetypealsoin?uencestheutilityofthetypesthataremoree?cient,andthusalsotheexpectedpro?tofthebuyerfromthosetypes.ThiscanbeseenfromEquation(1),whichsaysthattheexpectedutilityofasupplierisanincreasingfunctionofthelesse?cienttypes’quantities.Thereforeforthebuyerawardinganoptionquantitytoonetypecostssomepro?tfromthemoree?cienttypes.Basedonthisconsiderationthebuyerwillinduceadownwarddistortionofthecapacitydecisionfromthelevelthatwouldbeoptimalbasedonthebuyer’sutilityfunction.Thedownwardfactorinthescoringfunctioncanbedenotedby?(Q)>0,andthescoringruleiss(wo,we,Q)=(r?we)S(Q)?woQ??(Q).Considerthefollowingscoringrule:??QF(c(q))ˉG(q)dq(4)s(wo,we,Q)=(r?we)S(Q)?woQ?hf(c(q))

wherehisaconstant,andc(q)isthetypethatisawardedoptionquantityqintheoptimalˉ(q)=k/(r?J(c)).outcome:G

Proposition4.5WiththescoringruledescribedinEquation(4),theauctionachievesthesameoutcomeastheoptimalauctionmechanism.

ThestrategyofabidderinanEnglishauctionissimple.ThesupplierintypecwillbidtheoptionquantityfollowingLemma4.4,anddecreasewoand/orweeachtimeinthesmallestamounttooutbidthewinningcontract,untilthecontractbringszeropro?t.Thehighestscorethatasupplierccanreachisequaltou(Q)?(cS(Q)+kQ),withthetotalpaymentwoQ+weS(Q)equaltothetotalcostkQ+cS(Q).

10

5Auctionsforawholesaleprice-franchisefee(WF)contractWithanoptioncontractthebuyercanreservecertaincapacityatasuppliertoensuree?cientsupplywhenthecapacityisobservable.Butasupplier’spromiseonthecapacitycannotbeenforcedwhenthecapacityisunobservable.Thereforethecontractwithunobservablecapacityshouldnotinvolveanypromiseorcommitmentonthequantity,asthewholesaleprice,thepricethatthebuyerwillpaythesupplierforeachproductthatisprovided,istheonlycontracttermthatwillin?uencethesupplier’scapacitydecision.Ifthebuyerpromisesahigherwholesaleprice,thesupplierwillbuildmorecapacitybecauseofthehighermargin,butthemarginofthebuyerwillbelower.Thebuyer’sdesignofthewholesalepricehastotradeo?themarginofrevenueandthecapacityincentive.Inadditiontothewholesalepricethesupplycontractcanalsoincludeafranchisefeewhichisindependentoftheamountofsupply.Afranchisefeeallowsthebuyertoextractsome?xedamountofpro?tfromthesupplier.Thefranchisefeewillbehigherifthewholesalepriceislower.Supplierswithdi?erentproductioncostswilltradeo?thewholesalepriceandfranchisefeedi?erently.Combiningthesetwoattributesallowsthebuyertodi?erentiatethesuppliers’typesbyprovidingdi?erentpro?les.Wecallacontractinthisoriginalformawholesaleprice-franchisefee(WF)contract.

LetaWFcontractbedenotedby(w,t),wherewisthewholesalepricepaidbythebuyerandtisthefranchisefeepaidbythesupplier.GivenaWFcontract(w,t),asupplierchastodecidehercapacityQtooptimizeherexpectedutility(w?c)S(Q)?kQ?t,whichgivesˉ(QW(w,c))=k.TheexpectedutilityofthetheoptimalcapacityQW(w,c)satisfyingGssuppliercwiththecontractisπW(c)=(w(c)?c)S(QW(w,c))?kQW(w,c)?t,andthe

b=(r?w)S(Q(w,c)).expectedutilityofthebuyerisπWW

5.1Theoptimaldirectmechanism

InadirectmechanismthebuyerwillannounceaWFcontract(w(c),t(c))foreachtypeofsupplierc,andsuppliersbidbyreportingtheirtypes.Themoste?cientsupplierwillbeawardedthecontractcorrespondingtoherreportedtype.Asintheanalysisforoptioncontractauctions,wewill?rstderivetheconditionofanICmechanism,andthenreformtheexpectedutilityofthebuyerbasedontheICcondition,whichleadstotheoptimalICdirectmechanism.

s(ρ,γ)betheexpectedutilityofasupplierwiththetypeγbyreportingtypeρintheLetπWs(ρ,γ)=(w(ρ)?γ)S(Q(w(ρ),γ))?kQ(w(ρ),γ)?t.Letπs(ρ)=WFcontractauction,πWWWW??2?sssssssπW(ρ,ρ),πW,1(ρ,γ)=πW(ρ,γ),πW,2(ρ,γ)=πW(ρ,γ),andπW,12(ρ,γ)=πW(ρ,γ).Proposition5.1Anecessaryandsu?cientconditionofICisthat

s??(c)=?S(Q(c))(1?F(c))n?1,1.πW

s??2.πW,12(ρ,γ)≥0,whichisimpliedbyw(c)≤0.

11

Basedonthe?rstconditioninProposition5.1,theexpectedutilityofasuppliercinanoptimalincentivecompatiblemechanismis

sπW(c)=??ccˉS(QW(ρ))(1?F(ρ))n?1f(ρ)dρ(5)

whereQW(ρ)isthecapacitythatasupplierwithtypeρwillsetupgiventhecontractintheoptimalWFcontractauction.GivenEquation(5),theexpectedutilityofthebuyeris??ˉb=csπWc[(r?c)S(QW(c))?kQW(c)?π(c)]f(1)(c)dc,whichasbeforeisequalto

bπW=??ccˉ[(r?J(c))S(QW(c))?kQW(c)]f(1)(c)dc.(6)

TomaximizeherutilitythebuyershouldinducethecapacityinvestmentQW(c)bydesigningw(c)sothattheintegratedfunctioninEquation(6)ismaximized,iftheICconditioninProposition5.1canbesatis?ed.Maximizing(r?J(c))S(QW(c))?kQW(c)leadstotheˉ(QW(c))=k.Proposition5.2showsthatsuchcapacityinvestmentQW(c)thatsatis?esGcapacityinvestment,whichisthesameasintheoptimaloutcomewhencapacityisobservable,canactuallybeimplementedbyanoptimalWFcontractauctionwithunobservablecapacity.Proposition5.2AnoptimalWFcontractauctionwithunobservablecapacitiesimplementsanoptimaloptioncontractauctionwithobservablecapacities.InanoptimalWFcontractauction,thedesignofcontracts{(w(c),t(c))}satis?es

kF(c)w(c)=+c=r?f(c)G(Q(c))

??cˉ(7)

t(c)=ξ(Q(c))?cS(Q(ρ))(1?F(ρ))n?1dρ

(1?F(c))(8)

S(q)kˉ?1whereξ(q)=?q,andQW(c)=G()isthecapacitythatasupplierwillvoluntarily

choosestoset.

Onewouldexpectthatwhenasupplier’scapacityisunobservableandhencenotcontractable,theutilityofthebuyerwoulddecreasefromthesituationwithobservablecapacitysinceshehasonelesstermthatthecontractcanregulateupon.ButProposition5.2showsthatbycarefullydesigningthecontractformandtheauctionmechanism,thebuyerdoesnotloseutilitybecauseoflosingthiscontractableterm.Thebuyerinducesthesamecapacityinvestmentwiththewholesaleprice,andensuretheincentivecompatibilityofsuchcapacityinvestmentwiththefranchisefee.Ifthecontractonlyincludesthewholesaleprice,thecapacityinvestmentofasupplierwillbedi?erentbecausethenasuppliermaynotchoosethewholesalepricedesignedforhertype.

12

5.2Optimalauctionwithamenuofcontracts

TheWFcontractsdesignedforeachtypeofasupplierintheoptimaldirectmechanismcomposeanoptimalmenuofcontracts,andwiththismenuofcontracts,asupplierwithtypecwillselectthecontract(w(c),t(c)).

Proposition5.3GivenamenuofcontractsTWwhereTW(c)=(w(c),t(c))satis?esEqua-tion7and8,itisaBayes-NashequilibriumstrategyforasupplierctobidthecontractTW(c).TheauctionwiththemenuofcontractsTWresultsintheoptimaloutcome.

5.3Optimalauctionwithascoringrule

Letthescoringfunctionbede?nedasaquasi-linearfunction:sW(w,t)=?uW(w)+t.TheoptimalbidonthewholesalepricebyasupplierisgiveninLemma5.4,andisindependentofthescoreofthewholebid.

Lemma5.4Thewholesalepricewintheoptimalbidofasupplierwithtypecsatis?esdd[kQW(w,c)?(w?c)S(QW(w,c))]=uW(w)dwdw(9)

Toensurethewholesalepriceandhencethecapacityinvestmentarethesameasintheoptimaloutcome,thebuyerwoulddesignthefunctionuW(w)sothatEquation9issatis?ed

(c)atw=r?F

.Considerthefollowingscoringrule:

sW(w,t)=??w

α?S(QW(?,c(?)))d?+t(10)

whereαisaconstant,andc(w)isthetypecorrespondingtothewholesalepricewinthe

(c(w))optimalmechanism,i.e.,w=r?F

.

Proposition5.5WiththescoringruledescribedinEquation10,theauctionachievestheoptimaloutcome.

Asupplier’sbeststrategyissimple:Inthebeststrategyasuppliercwillalwaysbidthe(c)wholesalepricew(c)=r?F

followingEquation9.Asupplierwillsequentiallyincrease

thefranchisefeeuptothelevelthatbringszeropro?tinexpectationgiventhewholesaleprice.

13

6Electroniccontractingimplementation

Thissectionprovidesanoverviewofanimplementationofthemechanismsdiscussedinearliersections.We?rstpresenttheRETSINAarchitecture[18],amulti-agentplatformthatprovidesmuchoftheinfrastructureforautomatedcontracting.Wethenpresentthecontractnegotiationprocess,asitwouldtakeplacewithinRETSINAanddiscussthedesignofacontractingagent,responsibleforcoordinatingthenegotiationprocessandproducingthe?nal,executablecontract.

6.1TheRETSINAmulti-agentarchitecture

RETSINA(ReusableEnvironmentforTaskStructuredIntelligentNetworkedAgents)[18]providesanenvironmentforalooselycouplednetworkofsoftwareagentstointeracttosolveproblemsthatarebeyondtheindividualcapacitiesorknowledgeofeachproblemsolver.RETSINAenablesheterogeneousagentsthataredistributedacrossnetworkstocollaboratetoperformtasks.Itisthereforewell-suitedasaplatformtoimplementthecontractingmechanismsdiscussedinprevioussectionsofthepaper.

EachRETSINAagento?ersasetofservices,de?nedbytheagent’scapabilities.Inordertoaccomplishitstasks,eachagenthascommunicationandplanningmodules.Thecom-municationmodulesends,receivesandinterpretsmessagesandrequestsfromotheragents.Theplanningmoduletakesasetofgoals,suchassecuringacontract,andproducesaplanortaskstructuretosatis?estheagent’sgoals.RESTINAprovidesseveraldi?erentkindsofagentsthatinteracttocollectivelyaccomplishauser’sobjectives.WedescribetheRETSINAarchitecture,asusedforelectroniccontracting,below(Figure1).

电子商务英文阅读材料

In:Interface

AgentsBuyer/Supplier

Out:

ContractsTaskAgents

MiddleAgents

Information

AgentsFigure1:ElectronicContractingusingtheRETSINAmulti-agentarchitecture

Ourscenarioassumesasinglebuyerandmultiplesuppliers.Throughinterfaceagents,thebuyerandthesupplierssubmittheirpreferencesforcontractstothebuyerandsupplier

14

agentsrespectively.ThebuyerandsupplieragentsareimplementedastaskagentswithinRETSINA.Taskagentshelpusersperformtasks,formulateproblem-solvingplansandcarryouttheseplansbycoordinatingandexchanginginformationwithotheragents.Thebuyerandsupplieragentshaveanadditionalmodule,whichencapsulatesthenegotiationdecisionmodelsdiscussedinthispaper.Thedecisionmodelsusethepreferencesofthebuyertogenerateacontractingmechanism,forexampleamenuofcontractsorascoringrulefortheevaluationofcontracts.Itisthenpassedontoacontractingagent,whichlocatessupplieragentsthroughaMatchmakerandcoordinatesthecontractnegotiationprocess.

TheMatchmakerisaRETSINAmiddleagent[19],helpingmatchagentsthatrequestser-viceswithagentsthatprovideservicesinthesystem.Forexample,thecontractingagentcanquerytheMatchmakerforsupplieragentsthathaveregisteredwiththeMatchmakerpreviously.Thecontractingagentisitselfamiddleagent,inthatitcoordinatestheactualcontractnegotiation,matchingabuyeragentwiththebestsupplieragentanddrawingupanexecutablecontract.

Allagentsinvolvedinthecontractnegotiationprocessmaymakeuseofinformationagents,whichprovideaccesstoinformationfromheterogeneousinformationsources,suchasdatabasesandknowledgebases.Forelectroniccontracting,informationagentsprovidetheagentsin-volvedinthecontractnegotiationwithdomainknowledge,suchasthedemandforecastin-formation,capacitycostandthegeneralproductione?ciencyofsuppliers.Furthermore,theinformationagentsprovidegeneralknowledgeaboutdi?erentkindsofauctionmechanisms,suchasauctionswithamenuofcontracts,withscoringrules,?rstpriceandsecond-pricesealedbidauctions,etc.

Thus,severaldi?erentkindsofagentsparticipateinthecontractnegotiationprocess.Inthenextsection,wedescribethecontractnegotiationprocessindetail.

6.2TheContractNegotiationProcess

电子商务英文阅读材料

Figure2:TheContractNegotiationProcess

15

Thecontractnegotiationisamulti-agenttransaction,involvingabuyeragent,severalsupplieragents,acontractingagentandamatchmaker.Inordertoinitiateacontractnegotiationusingaparticularauctionprotocol,thebuyeragent?rstneedstolocateacontractingagentthatsupportsthedesiredauctionprotocol.ThenegotiationprocessthatfollowsisdisplayedinFigure2andissummarizedinthefollowingsteps:

1.Thebuyeragentcontactsthecontractingagenttoinitiateacontractnegotiation.Itsrequestincludesinformationaboutthesupplyorservicetocontracton,e.g.theproductsupplyforthenextdemandseason,thecontractform(e.g.anoptioncontractorwholesaleprice-franchisefee(WF)contract)andtheauctionprotocol.

2.ThecontractingagentsendsaqueryrequesttotheMatchmakeraboutsupplieragents.

3.TheMatchmakerreturnsalistofsupplieragentstothecontractingagent.

4.Thecontractingagentcontacts(asubsetof)thesupplieragentswithcontractinginformation,suchasthecontractingrequirementanddemand,thecontractformandtheauctionprotocol.

5.Thesupplieragentsinformthecontractingagentoftheirinterestinparticipatinginthecontractnegotiation.

6.Thecontractingagentsendsnegotiationinformationtoallbuyerandsupplieragents.Thenegotiationinformationconsistsofthenumberofbiddersparticipatinginthenegotiationandacontracttemplate,whichdescribesthecontractparameters,suchaspriceofgoods,andwhethertheyareundernegotiation.

7.Thebuyeragentsendsthecontractingagentthemechanism,forexamplethemenuofcontractsorascoringrule,thatwillbeusedforthecontractnegotiation.

8.Thecontractingagentsendsthecontractingmechanisminformationtothesupplieragents.

9.Thesupplieragentsrespondbysubmittingcontractbidstothecontractingagent.

10.Thecontractingagentselectsthewinningbidandinformsallpartiesofthewinningbid.

11.Inthecaseofadynamicauctionwithmultiplerounds,steps9and10(thesupplieragents

submitcontractbidsandthecontractingagentselectsthewinningbid)arerepeated.Afterthelastroundofthecontractingprocess,thecontractingagentconstructsanexecutablecontractfromthecontracttemplateandtheresultsofthecontractnegotiation.Thisexecutablecontractissenttoboththebuyeragentandthewinningsupplieragent.

Thecontractingagentgeneratesacontracttemplatefromthebuyeragent’sinformationinstep1andtheexecutablecontractinstep11,usingitsknowledgeaboutcontractsandtheexecutionenvironmentofthecontract.Aninterestingapproachtotherepresentationofcontractknowledge,contractsandcontracttemplatesisprovidedbytheContractBot[15]framework,whichusesdeclarativerepresentationsofacontracttemplatetonegotiateafullexecutablecontract.ContractBotusesCourteousLogicPrograms(CLP)[14]torepresentcontractsandcontracttemplates.Courteouslogicprogramsenablethespeci?cationofthescopeofpotentialcon?ictwithincontracts,suchasmutuallyexclusivecontractcon?gura-tions,andspeci?cationofpartially-orderedprioritiesbetweenrules,whichisusedtoresolveinconsistenciesbetweentherules.

16

Acknowledgement

ThisworkwassupportedinpartbyAFOSRgrantF49620-01-1-0542andAFRL/MNKgrantF08630-03-1-0005.

References

[1].

[2]S.AngelovandP.Grefen.B2Becontracthandling-asurveyofprojects,papersandstandards.Technicalreport,UniversityofTwente,TheNeterlands.

[3]G.CachonandF.Zhang.Fastdeliverythroughcompetingsuppliers.MSOM2003.

[4]Y.-K.Che.Designcompetitionthroughmultidimensionalauctions.RANDJournalofEconomics,24(4):668–680,1993.

[5]F.Chen.Auctioningsupplycontracts.Technicalreport,GraduateSchoolofBusiness,ColumbiaUniversity,2001.

[6]S.DasguptaandD.F.Spulber.Managingprocurementauctions.InformationEconomicsandPolicy,4:5–29,1989/90.

[7]Y.B.DawnBarnes-SchusterandR.Anupindi.Optimizingdeliveryleadtime/inventoryplacementinatwo-stageproduction/distributionsystem.Technicalreport,UniversityofChicago,2000.

[8]R.A.-S.EstherDavidandS.Kraus.AnEnglishAuctionProtocolforMulti-AttributeItems,volume2531ofAgentMediatedElectronicCommerceIV:DesigningMechanismsandSystems,LNAI,pages52–68.2002.

[9]R.A.-S.EstherDavidandS.Kraus.Protocolsandstrategiesforautomatedmulti-attributeauction.InProceedingsofthe3rdInternationalConferenceonAutonomousAgentsandMulti-AgentSystems(AAMAS2002),July2002.

[10]R.A.-S.EstherDavidandS.Kraus.Bidders’strategyformulti-attributesequential

englishauctionwithadeadline.InProceedingsofthe3rdInternationalConferenceonAutonomousAgentsandMulti-AgentSystems(AAMAS2003),July2003.

[11]D.FudenbergandJ.Tirole.GameTheory.MITPress,1991.

[12]V.Krishna.AuctionTheory.AcademicPress,2002.

[13]D.Lucking-ReileyandD.F.Spulber.Business-to-businesselectroniccommerce.Journal

ofEconomicPerspectives,15(1):55–68,Winter2001.

17

[14]D.M.Reeves,B.N.Grosof,M.P.Wellman,,andH.Y.Chan.Towardsadeclarative

languagefornegotiatingexecutablecontracts.InProceedingsoftheAAAI-99WorkshoponArti?cialIntelligenceinElectronicCommerce(AIEC-99),July1999.

[15]D.M.Reeves,M.P.Wellman,andB.N.Grosof.AutomatedNegotiationfromDeclarative

ContractDescriptions.November2002.

[16]K.Rosling.Inventorycostratefunctionswithnonlinearshortagecosts.Operations

Research,50(6):1007–1017,2002.

[17]J.SunandN.Sadeh.Coordinatingmulti-attributereverseauctionssubjecttotemporal

andcapacityconstraints.InProceedingsof2004HawaiiInternationalConferenceonSystemSciences(HICSS-37),January2004.

[18]K.Sycara,K.Decker,A.Pannu,M.Williamson,andD.Zeng.Distributedintelligent

agents.IEEEExpert,December1996.

[19]K.Sycara,K.Decker,andM.Williamson.Middle-agentsfortheinternet.InProceedings

ofIJCAI-97,January1997.

[20]W.E.WalshandM.P.Wellman.Decentralizedsupplychainformation:Amarket

protocolandcompetitiveequilibriumanalysis.JournalofArti?cialIntelligenceResearch,19:513–567,2003.

Appendix

ProofofLemma4.1:

ssNecessary:Ifthecontractisincentivecompatible,πO(c)=maxc??πO(c??,c).Withoutlossofgenerality

ssssssletc??>c.ICimpliesthatπO(c??,c)?πO(c??,c??)≤πO(c,c)?πO(c??,c??)≤πO(c,c)?πO(c,c??),whichis

ss(c??,c??)≤(c???c)S(QO(c))(1?F(c))n?1,equivalentto(c???c)S(QO(c??))(1?F(c??))n?1≤πO(c,c)?πOsπs(c,c)?π(c??,c??)S(QO(c??))(1?F(c??))n?1≤≤S(QO(c))(1?F(c))n?1.ThereforeS(QO(c))(1?

s??F(c))n?1isadecreasingfunctionofc.Whenc??→??c,theinequalityimpliesthatπO(c)=?S(QO(c))(1?cn?1sssn?1F(c)).LetπO(ˉc)=u0,thenπ(c)=π(ˉc)+c?S(Q(ρ))(1?F(ρ))dρ.ˉ??cssSu?cient:Assumetwotypesc??>c.GivenEquation1,πO(c??)?πO(c)=c??S(QO(ρ))(1?F(ρ))n?1dρ.??c??Buttherighthandsideisnogreaterthan≤c?S(QO(c??))(1?F(c??))n?1dρ=S(QO(c??))(1?

ssF(c??))n?1(c???c),sinceQO(c)≥QO(c??).ThereforeπO(c)≥πO(c??)?S(QO(c??))(1?F(c??))n?1(c?c??)=

s[We(c??)+Wo(c??)?kQO(c??)?cS(QO(c??))](1?F(c??))n?1=πO(c??,c).Hencethecontractisincentive

compatible.

ProofofProposition4.1:Weonlyneedtoprovethatthemechanismisincentivecompatible,sinceQO(c)inEquation2maximizesthebuyer’sexpectedutilitybasedontheassumptionthatthemech-

sssanismisincentivecompatible.WewillproveICbyshowingthatπO(c??,c)≤πO(c).πO(c??,c)=??cˉ

[(we(c)?c)S(Q(c))+(wo(c)?k)QO(c)](1?F(c))??????????n?1=[c??S(QO(ρ))(1?F(ρ))n?1dρ

+(c???c)S(QO(c??))](1?

18

F(c??))n?1=??cˉn?1??????n?1sS(Q(ρ))(1?F(ρ))dρ+(c?c)S(Q(c))(1?F(c)).π(c)=S(Q(ρ))(1?O??cc????cF(ρ))n?1dρ.Thenπs(c)?πs(c??,c)=cS(Q(ρ))(1?F(ρ))n?1dρ?(c???c)S(Q(c??))(1?F(c??))n?1≥??c??S(Q(c??))(1?F(c??))n?1dρ?(c???c)S(Q(c??))(1?F(c??))n?1=0.Thereforeasupplierwillbidctruthfully.??cˉ

Comparinganoptimaloptioncontractauctionandadvanced-purchasecontractauction:

Basedon[5],inanoptimaladvanced-purchasecontractmechanism,thequantityQA(c)thatthe

ˉ(QA(c))=k+J(c),theexpectedutilityofbuyerwillbuyfromawinnerwithtypecsatis?esthatG??cˉsn?1basuppliercisπA(c)=cQA(ρ))(1?F(ρ))dρ,andtheexpectedutilityofthebuyerisπA=??cˉ[rS(QA(c))?(k+J(c))QA(c)]f(1)(c)dc.c

LetIA(QA,c)=rS(QA(c))?QA(c)(J(c)+k)andIO(QO,c)=S(QO(c))(r?J(c))?kQO(c).Then??c??cˉˉbbπO=cIO(QO,c)f(c)dc,πA=cIA(QA,c)f(c)dc.QO(c)≥QA(c)becauseG(QA(c))?G(QO(c))=

bb+J(c)?r)≤0.ThenπO≥πA.ThisisbecauseIO(QO,c)≥IO(QA,c).ButIO(QA,c)?

IA(QA,c)=(QA(c)?S(QA(c)))J(c)≥0.J(c)(k

ProofofProposition4.3:Itsu?cestoprovetheincentivecompatibilityandfollowstheproofofProposition4.2.

ProofofLemma4.4:Foragivenscores,asupplierwillchooseqtomaximize(we?c)S(q)+(wo?k)q

?subjectto(r?we)S(q)?woq??(q)=s.LetW=weS(q)+woq.If((r?c)S(q)?kq??(q))=0,

forexample,rS??(q)????(q)>cS??(q)+k,thenwecanhaveq??=q+??for??>0verysmall,andW??=W+(rS(q??)+?(q??))?(rS(q)+?(q)).WithW??andq??,thescoreisthesame,butthesupplierhashigherutilitybecauseW???W?[(cS(q??)?kq??)?(cS(q)?kq)]=(rS(q??)+?(q??))?(rS(q)+?(q))?[(cS(q??)?kq??)?(cS(q)?kq)]=(rS??(q)????(q))???(cS??(q)+k)??>0.

ProofofProposition4.5:FollowingLemma4.4,asupplierwithtypecwillchoosetheoptionquantity

?QO(c)tomaximize(r?c)S(q)?kq??(q).Thisisbecause((r?c)S(q)?kq??(q))=(r?c?

independentofthescore.

Letsˉ(c)=(r?c)S(QO(c))?kQO(c)??(QO(c))bethemaximumscorethatcanbereachedbyasupplierwithtypec.Atthecontractwiththemaximumscoretheutilityofasupplieriszero.InanEnglishauction,themoste?cientsupplierwillbethewinnerbecausethemaximumscoreofamoree?cientsupplierishigher.Thereforetheprobabilityofbeingthewinner,andthecapacityinvestmentofthewinner,inanEnglishauctionarethesameasintheoptimalmechanism.FollowingtheproofofProposition4in[4],theEnglishauctionwiththescoringruleEquation4implementstheoptimalmechanism.

ProofofProposition5.1:ThecapacitydecisionofasupplierwithtypecisQW(c??,c)ifshereports

stypec??andisselectedasthewinner.πW(c??,c)=[(w(c??)?c)S(Q(c??,c))?kQW(c??,c)?t(c??)][1?

k?s???????????ˉ(QW(c??,c))=ˉF(c??)]n?1,G,πW(c,c)=[(w(c)?c)G(QW(c,c))QW(c,c)?S(QW(c,c))?

?kQW(c??,c)][1?F(c??)]n?1=?S(QW(c??,c))[1?F(c??)]n?1.

Necessary:

?sss??ICimpliesthatc=argmaxc??πW(c??,c).Bytheenveloptheorem,itfollowsthatπW(c)=πW(c??,c)|c??=c.

s??ˉ(QW(c))?QW(c??,c)|c??=c?S(Q(c))?k?QW(c??,c)|c??=c][1?F(c)]n?1=HenceπW(c)=[(w(c)?c)G?S(QW(c))[1?F(c)]n?1andthe?rstconditionshouldbesatis?edinanICmechanism.Actually1F(Q?(QO(c)))ˉO)G(q)?kf(QO(QO(c)))whichiszeroifq=QO(c).ThereforeasupplierwithtypecwillchooseQO(c)

19

ss??ssthe?rstconditionisequivalenttoπW,1(c,c)=0.ItisbecauseπW(c)=πW,1(c,c)+πW,2(c,c),and

s??sn?1sπW(c)=πW,ifπW,2(c,c)=?S(QW(c))[1?F(c)]1(c,c)=0,whichisimpliedbyIC.

ssssIfthemechanismisincentivecompatible,πW(c??,c)≤πW(c,c)andπW(c,c??)≤πW(c??,c??).Adding

ssssupthesetwoinequalitiesgivesπW(c??,c)?πW(c??,c??)≤πW(c,c)?πW(c,c??).Itisequivalentto??c????cssπ(ρ,γ)≤0,andimpliesthesecondconditionπW,12(ρ,γ)≥0.cc??W,12

Su?cient:

ssNowsupposeπW,12(ρ,γ)≥0andπW,1(c,c)=0.IfamechanismisnotIC,

ssπW(c??,c)>πW(c,c)???c??

?

?

?πs(ρ,c)dρ>0c??W,1??css[π(ρ,c)?πW,1(ρ,ρ)]dρc??W,1??c??csπ(ρ,γ)dγdρ>0ρW,12csπW,12(ρ,γ)<0.>0

sItcontradictstheconditionπW,12(ρ,γ)≥0.Thereforethe?rstandsecondconditionsaresu?cient

foranICmechanism.

?sn?1ˉ(QW(ρ,γ))?QW(ρ,γ)(1?F(ρ))n?1+(n?ButπW,]=?G12(ρ,γ)=?[S(QW(ρ,γ))(1?F(ρ))?1n?2??ˉ(QW(ρ,γ))=1)S(QW(ρ,γ))(1?F(ρ))f(ρ).Ifw(c)≤0,thenQW(ρ,γ)≤0becauseG.

Thereforew(c)≤0implies??sπW,12(ρ,γ)≥0.

ProofofProposition5.2:Itsu?cestoprovethatthismechanismisincentivecompatible.Basedon

(n?1)f(c)t??(c)dF(c)??ˉEquation8,?[t(c)?kξ(QW(c))]W=?=w(c).BecauseG(QW(c))=WF(c))(q)g(q)]=?S(QW(c))(1?F(c)),givenξ(q)=S

Therefore(t?kξ(QW(c)))(1?.??cˉsF(c))n?1=cS(Q(ρ))(1?F(ρ))n?1dρ.Thentheexpectedutilityofasuppliercis:πW(c)=[(w(c)?

kn?1c)S(QW(c))?t(c)?kQW(c)](1?F(c))n?1=[=WS(QW(c))?t(c)?kQW(c)](1?F(c))??cˉ[kξ(QW(c))?t(c)](1?F(c))n?1=cS(Q(ρ))(1?F(ρ))n?1.The?rstconditioninProposition5.1

issatis?ed.BasedontheassumptionthatF(c)/f(c)isanincreasingfunctionofc,w??(c)<0,andsothesecondconditionisalsosatis?ed.k??,w(c)n?1=dk+c)(=1+kg(QW(c))Q??W(c).Wn?1??Thesetwoequalitiessuggestd[(t?kξ(QW(c)))(1?

ProofofProposition5.3:Itsu?cestoprovetheincentivecompatibilityandfollowstheproofofProposition5.2.

ProofofLemma5.4:ItissimilartotheproofofseparabilityinLemma4.4.IfEquation9doesnothold,thesuppliercanalwaysincreasewanddecreasetiftherighthandsideisbigger,ordecreasewandincreasetifthelefthandsideisbigger,sothatthescoredoesnotchangebuttheutilitybasedonthecontractisincreased.

ProofofProposition5.5:FollowingLemma5.4,asupplierwithtypecwillchoosethewholesaleprice

(c)d??w(c)=r?F

becauseu(w)=S(QW(w,c(w)))isequalto[(w?c)S(QW(w,c))?kQW(w,c)]=

S(QW(w,c))whenw=w(c).HenceasupplierwithtypecwillbuildcapacityQW(c)thatisequaltotheoutcomeinanoptimalmechanism.Sincethemoste?cientsupplierwillbethewinnerinanEnglishauction,theEnglishauctionwiththescoringruleEquation10implementstheoptimalmechanism.

20

更多类似范文
┣ Love or Money读后感 2600字
┣ 读后感 1100字
┣ 英美小说读后感 8100字
┣ 《傲慢与偏见》读后感 4400字
┣ 更多love of life 读后感
┗ 搜索类似范文

更多相关推荐:
《土拨鼠日》英文读后感3900字

It39snodoubtthatitisasuccessfulmovieItonlymakespeoplelaughatwhatalifeleadingactorhasbutalsoitledpeopletoconsidertha...

《了不起的盖茨比》英文读后感3700字

WhyisGatsbygreatAfterfinishingthisnovelthisquestionkeepmepuzzledforalongtimeIsthisanironyAsaresultofdeepthinkingand...

书虫系列英文读后感44800字

HavesomekindoflovebecomeblindbuthypocriticalinthisabnormalsocietyBeunbearableCatherinevanitythinandweakbu...

专栏推荐
大家在关注

地图地图CC