科技英語第二次課-game-theory課件

Unit1MathematicsUnit1Mathematics1Warming-upMathematicshasawideapplication,suchascomputer,economy.Nowithasbeenbroadentheoreticallyandappliedtomanysocialproblems.Ithasdrivenarevolutionineconomictheory.Ithasalsofoundapplicationinsociologyandpsychology,andestablishedlinkswithevolutionandbiology.OnesignificantapplicationisGameTheorywhichreceivedspecialattentionwiththeawardingoftheNobelPrizeineconomicstoJohnNash.Warming-upMathematicshasawi2TextAGameTheory博弈論TextAGameTheory3GameTheoryGametheoryisthemathematicalanalysisofanysituationinvolvingaconflictofinterest,withtheintentofindicatingtheoptimalchoicesthat,undergivenconditions,willleadtoadesiredoutcome.

GameTheoryGametheoryisthe4Itattemptstodeterminemathematicallyandlogically

theactionsthat“players”shouldtaketosecurethebestoutcomesforthemselvesinawidearrayof“games”.它試圖以數(shù)學(xué)和邏輯的方法幫助博弈者作出決策，使他們在一系列紛繁復(fù)雜的博弈中保證利益的最大化。

Itattemptstodeterminemathe5zero-sumgamesIngametheoryandeconomictheory,zero-sumdescribesasituationinwhichaparticipant'sgainorlossisexactlybalancedbythelossesorgainsoftheotherparticipant(s).Examples:賭博zero-sumgamesIngametheory6Moretypicalaregameswiththepotentialforeithermutualgainormutualharm,aswellassomeconflict.更多具有代表性的例子可能會導(dǎo)致共同得利博弈和共同損失博弈，同樣的情況還會發(fā)生在另外一些沖突中。Moretypicalaregameswithth7GametheorywaspioneeredbyPrincetonmathematicianJohnvonNeumann.更多具有代表性的例子可能會導(dǎo)致共同得利博弈和共同損失博弈，同樣的情況還會發(fā)生在另外一些沖突中。GametheorywaspioneeredbyP8PrincetonPrincetonUniversityisaprivateresearchuniversitylocatedinPrinceton,NewJersey,UnitedStates.TheschoolisoneoftheeightuniversitiesoftheIvyLeagueandisconsideredoneoftheColonialColleges.PrincetonPrincetonUniversity9JohnvonNeumannAHungarian-bornAmericanmathematicsandmadecontributiontoquantumphysics,functionalanalysis,settheory,economics,computerscience,topology,numericalanalysis,hydrodynamics,statisticsandmayothermathematicalfieldsasoneofwordhistory’soutstandingmathematicians.JohnvonNeumannAHungarian-b10Whenthinkingabouthowotherswillrespond,onemustputoneselfintheirshoes,andthinkastheywould;oneshouldnotimposeone’sownreasoningonthem.在考慮其他博弈者會如何應(yīng)對時，博弈者必須能設(shè)身處地地?fù)Q位思考，而不能把自己的主觀判斷強(qiáng)加于人。Whenthinkingabouthowothers11tic-tac-toe井字棋Tic-tack-toeisapencil-and-papergameinwhichtwoplayersalternatelyputcrosses(0)andcircles(×)inoneofthecompartmentsofasquaregridofninespaces.Theplayerwhosucceedsinplacingthreerespectivemarksinahorizontal,verticalordiagonalrowwinsthegame.tic-tac-toe井字棋Tic-tack-toei12Incontrasttothelinearchainofreasoningforsequentialgames,agamewithsimultaneousmovesinvolvesalogicalcircle.與連續(xù)策略博弈的線性思維不同，聯(lián)立策略的博弈涉及邏輯循環(huán)。Incontrasttothelinearcha13JohnNashJohnForbesNashJr.(bornJune13,1928)isanAmericanmathematicianandeconomistwhoseworksingametheory,differentialgeometry,andpartialdifferentialequationshaveprovidedinsightintotheforcesthatgovernchanceandeventsinsidecomplexsystemsindailylife.JohnNashJohnForbesNashJr14Nashequilibrium納什均衡，又稱為非合作博弈均衡ANashequilibrium,namedafterJohnNash,isasetofstrategies,oneforeachplayer,suchthatnoplayerhasincentivetounilaterallychangeheraction.Nashequilibrium納什均衡，又稱為非合作博弈15Whenwesaythatanoutcomeisanequilibrium,thereisnopresumptionthateachperson’sprivatelybestchoicewillleadtoacollectivelyoptimalresult.當(dāng)我們把博弈的結(jié)果表述為一種均衡的時候，并不能假定博弈的每個參與者的個人最佳策略將帶來共同的最優(yōu)化結(jié)果。Whenwesaythatanoutcomei16Nash’snotionofequilibriumremainsanincompletesolutiontotheproblemofcircularreasoninginsimultaneous-movegames.納什關(guān)于均衡的概念還不能完全解決聯(lián)立策略博弈中邏輯循環(huán)的問題。Nash’snotionofequilibrium17Andthedynamicprocessthatcanleadtoanequilibriumisleftunspecified.納什均衡還沒有清除地說明關(guān)于導(dǎo)致均衡的動態(tài)過程。Andthedynamicprocessthatc18Prisoners’dilemma囚徒困境Ingametheory,theprisoners’dilemmaisatypeofnon-zerogameinwhichtwoplayerscancooperatewithordefecttheotherplayer.Prisoners’dilemma囚徒困境19Prisoners’dilemmaTwosuspectsarearrestedbythepolice.Thepolicehaveinsufficientevidenceforaconviction,and,havingseparatedbothprisoners,visiteachofthemtoofferthesamedeal.Ifonetestifies(defectsfromtheother)fortheprosecutionagainsttheotherandtheotherremainssilent(cooperateswiththeother),thebetrayergoesfreeandthesilentaccomplicereceivesthefull8-yearsentence.Ifbothremainsilent,bothprisonersaresentencedtoonlyoneyearinjailforaminorcharge.Ifeachbetraystheother,eachreceivesafive-yearsentence.Eachprisonermustchoosetobetraytheotherortoremainsilent.Eachoneisassuredthattheotherwouldnotknowaboutthebetrayalbeforetheendoftheinvestigation.Ifweassumethateachplayercaresonlyaboutminimizinghisorherowntimeinjail,howshouldtheprisonersact?Prisoners’dilemmaTwosusp20警方逮捕A、B兩名嫌疑犯，但沒有足夠證據(jù)指控二人入罪。于是警方分開囚禁嫌疑犯，分別和二人見面，并向雙方提供以下相同的選擇：若一人認(rèn)罪并作證檢舉對方（相關(guān)術(shù)語稱“背叛”對方），而對方保持沉默，此人將即時獲釋，沉默者將判監(jiān)8年。若二人都保持沉默（相關(guān)術(shù)語稱互相“合作”），則二人同樣判監(jiān)一年。若二人都互相檢舉（互相“背叛”），則二人同樣判監(jiān)5年。囚徒困境假定每個參與者（即“囚徒”）都是利己的，即都尋求最大自身利益，而不關(guān)心另一參與者的利益。警方逮捕A、B兩名嫌疑犯，但沒有足夠證據(jù)指控二人入罪。于是警21Gametheoryquantifiesthisinsightanddetailstherightproportionsofsuchmixtures.博弈論為提高洞察力和掌握混合性策略恰當(dāng)?shù)幕鸷蛱峁┝藚⒖肌ametheoryquantifiesthisin22CortésHernánCortéswasaSpanishexplorerwhoisfamousmainlyforhismarchacrossMexicoandhisconqueringoftheAztecEmpireinMexico.CortésHernánCortéswasa23strategyofbrinkmanshipBrinkmanshipisthepracticeofpushingadangeroussituationtothevergeofdisasterinordertoachievethemostadvantageousoutcome.Itoccursininternationalpolitics,foreignpolicy,labourrelations,and(incontemporarysettings)inmilitarystrategyinvolvingthethreateneduseofnuclearweapons.strategyofbrinkmanshipBrink24ThomasSchellingThomasCrombieSchelling(born14April1921)isanAmericaneconomistandprofessorofforeignaffairs,nationalsecurity,nuclearstrategy,andarmscontrolattheSchoolofPublicPolicyatUniversityofMaryland,CollegePark.Hewasawardedthe2005NobelMemorialPrizeinEconomicSciences(sharedwithRobertAumann)for"havingenhancedourunderstandingofconflictandcooperationthroughgame-theoryanalysis."ThomasSchellingThomasCrombie25WinstonChurchillHewastheEnglishstatesmanandauthor,bestknownasPrimeMinisteroftheUnitedKingdomduringtheWWWII.Well-knownasanorator,strategist,andpolitician,ChurchillwasonetheimportantleadersinmodernBritishandworldhistory.Hewonthe1953NobelPrizeinLiteratureforhismanybooksonEnglishandworldhistory.WinstonChurchillHewastheEn26Toconveyinformation,useanactionthatiscredible“signal”,somethingthatwouldnotbedesirableifthecircumstanceswereotherwise.Forexample,anextendedwarrantyisacrediblesignaltotheconsumerthatthefirmbelievesitisproducingahigh-qualityproduct.如果要公布信息，就要采用傳遞可信信息的策略，而且形勢發(fā)生變化時策略也必須相應(yīng)進(jìn)行改變，例如，提供長期的質(zhì)量保證是企業(yè)生產(chǎn)高質(zhì)量產(chǎn)品信心的顯示，對于消費(fèi)者來說也是一個可以信賴的信號。Toconveyinformation,usean27ExerciseIVMultipleChoice1.D2.D3.D4.B5.B

6. C7. D8. A9. B10. DExerciseIVMultipleChoice1.28ExerciseVBlankFilling1.prime 2.interactive3.purchasing4.journal5.enhances6.abuse7.methodology8.modeling9.preferences10.constructingExerciseVBlankFilling1.pri29ExerciseVICloze1. B2. A3. C4. D5. A6. C7. D8. B9. A10. C11. D12. B13. A14. C15. D16. B17. D18. A19. D20. DExerciseVICloze1. B11. D30TranslationPractice(P.18)1.互贏博弈和互敗博弈2.連續(xù)策略博弈3.聯(lián)立策略博弈4.直線推理5.循環(huán)推理6.納什均衡7.支配化策略8.最優(yōu)化結(jié)果9.合作破裂10.邊緣化策略TranslationPractice(P.18)1.互31TranslationPractice(P.18)1.pu