Overview
Ineconomics
UncertaintyreferstothefactthateconomicactorscannotaccuratelyknowtheresultsofcertainThereismorethanonepossibleresultofadecisionoftheactor,whichwillproduceuncertainty.Uncertainty,theconceptofriskmanagementineconomics,referstothefactthateconomicentitiescannotbesureaboutthedistributionandstatusoffutureeconomicconditions(especiallygainsandlosses).
Quantummechanics
Inquantummechanics,uncertaintyreferstotheuncertaintyofmeasuringphysicalquantities,becauseundercertainconditions,somemechanicalquantitiescanonlybeintheireigenstatesOntheabove,thedisplayedvaluesarediscrete.Therefore,whenmeasuringatdifferenttimes,itispossibletogetdifferentvalues,andtherewillbeuncertainvalues.Thatistosay,whenyoumeasureit,youmaygetthisvalue,youmaygetThatvalue,thevalueobtainedisuncertain.Onlybymeasuringtheeigenstateofthismechanicalquantitycantheexactvaluebeobtained.
Inclassicalphysics,thepositionandmomentumofaparticlecanbeusedtoaccuratelydescribeitsmotion.Knowingtheaccelerationatthesametime,youcanevenpredictthepositionandmomentumoftheparticleatanytimeinthefuture,therebydrawingatrajectory.Inmicrophysics,uncertaintytellsusthatifwewanttomeasurethepositionofaparticlemoreaccurately,themeasuredmomentumisevenmoreinaccurate.Inotherwords,itisimpossibletoaccuratelymeasurethepositionandmomentumofaparticleatthesametime.Therefore,thetrajectorycannotbeusedtodescribethemovementofparticles,butthemicroscopicworldhasthesameobjectivelawsasthemacroworld,independentofconsciousness.Thisisthespecificexplanationoftheuncertaintyprinciple.
Commonuncertaintyinquantummechanicsisabouttheuncertainrelationshipbetweencoordinatesandmomentum,andbetweentimeandenergy.Infact,theexactvalueofanytwoincompatibilitycannotbedeterminedatthesametime.Thishasnothingtodowithmeasurement,itistheessentialproblemofthemicroworld.
Don'ttrytoexplaintheuncertaintythroughmeasurementandothermethods.Anymeasurementmethodwillintroducenewerrors.Thereisafundamentaldifferencebetweenerroranduncertainty.Inaddition,forphenomenasuchasuncertaintythatcannotbeobservedinthemacroworld,thisisrelatedtotheobservablemeasurementaccuracy,soitisonlymoreobviousinthemicroworld.
Informationtheory
Ininformationtheory,uncertaintyisaphysicalquantitythatcharacterizeshowreliablearandomvariableoccurs.Entropyisgenerallyusedtocalculatethisphysicalquantity,denotedasH(X),whereXisarandomvariable.WhenH(X)=0,Xisverycertain,thatis,Xisacertainvalueatthistime.WhenH(X)=1,Xisveryuncertain,thatis,thevalueofXisveryuncertainwhichvalueitis.
Machinelearning
Inmachinelearningproblems,modelsoftenneedtolearnagoodrepresentationfrommassivetrainingdata.Onemajorchallengeisthatmanualdataannotationisoftensemanticallyambiguous.Therefore,somepapersuseuncertaintytodescribeandcorrecterrorsinlabeling,sothatthemodelreducestheweightoflearninguncertainsamplesandshiftstolearningmoreaccuratelabels.
BookInformation
Title:Uncertainty
Author:Gelaizhe·Morgan
Press:PekingUniversityPress
Publicationtime:January1,2011
ISBN:9787301180327
Format:16open
Price:56.00yuan
p>Introduction
"Uncertainty"isspeciallydesignedforfourtypesofreaders:1.Professionalanalystswhobelieveintheimportanceofdealingwithuncertaintyandwanttolearnhowtodoit;2.Studentswhoarejustgettinginvolvedinquantitativepolicyanalysisandwanttodevelopgoodskillsandhabits;3.Managersanddecisionmakerswhoareunlikelytodotoomuchanalysisinpersonbutwanttounderstandtheexistingtechniquesmorethoroughlyinordertoknowwhatisrequiredandhowtoappraisetheresults;4.Thoseskilledanalystswhodealwiththisproblemintheirdailyworkandhaveagrowingnumberofskilledanalysts."Uncertainty"summarizesthebasicconceptsandskillsinthisfield,whichcanbeusedasacompletereferencetextbookattheirhands.Wehopethattheseconceptsandthesubsequentcontentwillbringallreadersthehappinessandchallengeswehaveintheprocessofconceiving,writingandsynthesizing"Uncertainty".
Abouttheauthor
Author:(U.S.)GladzerMorgan(U.S.)MaxHenry(U.S.)MitchellSmallTranslator:WangHongman
GraceMorgan,professoratCarnegieMellonUniversity.ServedasChairmanoftheScientificAdvisoryBoardoftheUSEnvironmentalProtectionAgencyandChairmanoftheScienceandTechnologyBranchoftheInternationalRiskManagementCouncil.MaxHenryisanassociateprofessorintheDepartmentofMedicalInformation,StanfordUniversitySchoolofMedicine.MitchellSmallisaprofessorofenvironmentalengineering,civilengineering,engineering,andpublicpolicyintheSchoolofPublicAdministrationatCarnegieMellonUniversity.Thethreescholarsco-authoredthebook"Uncertainty",whichisaguidefordealingwithuncertaintyinquantitativeriskanalysisandpolicyanalysis.
ProfessorWangHongman,PhDsupervisorofPekingUniversity.Hehaspresidedoverthecompletionof15scientificresearchprojects,including5atthenationallevel,withcomplementaryteachingandresearch,fruitfulresults,andmanyawards.Heistheauthorofthetrilogyof"HealthintheBigCountry","GlobalHealthInternationalHealthStrategy";publishedmorethan50papers,1StateCouncilconsultationreport,1BeijingMunicipalGovernmentconsultationreport.ThescientificresearchresultshaveattractedtheattentionofrelevantleadersofthecentralgovernmentandBeijingandrelevantdepartments.Someoftheimportantviewsandsuggestionshavebeenincludedinthe"AchievementsReport"ofthecountry,andhavebeenadoptedbyrelevantgovernmentdecisions.In2001,hewontheNewCenturyPopulationCulturePromotionHundredOutstandingWomenAward;in2004,heledthenationalmajorproject"China'sruralhealthsecuritysystempolicyresearch"chiefexpert;in2008,washiredbytheMinistryofHealthasanexpertin"HealthyChina2020StrategicPlanningResearch";2009Electedasapioneerofeducationinthecapital.
BookCatalog
ChapterOneIntroduction
ChapterTwoRecentMilestones
ChapterThreeQuantitativePolicyAnalysisOverview
Chapter4TheNatureandSourceofUncertainty
Chapter5ProbabilityDistributionandStatisticalEstimation
Chapter6Thehumanjudgmentofuncertaintyhasuncertainty
ChapterSevenProbabilityEvaluation
ChapterEightUncertaintyPropagationandAnalysis
ChapterNineUncertaintyGraphicExpression
Chapter10Analytica:UncertaintyAnalysisandModelCommunicationSoftwareTool
Chapter11LargeandComplexModels
Chapter12KnowingWhatYouKnowLittleValue
Postscript
Index