introduction to ai - ninth lecture
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ModernApproachesandTechniques
HybridArchitectures0 Hybrid Architectures:combiningthevariousagentarchitectures.0 E.g.combiningreflexcomponentswithknowledge‐basedcomponents.
0 Compilation:convertdeclarativeinformationatthedeliberatelevelintomoreefficientrepresentations,eventuallyreachingthereflexlevel.0 Soar(1987),Theo(1990).0 Solutionstonewproblemsarederivedbydeliberation,butarecompiledandstoredatthereflexlevelforsolvingfutureoccurrencesofsimilarproblems.
Real‐TimeAI0 Increasinglymorecomplexenvironments:partiallyobservable,multiagent,stochastic,sequential,dynamicand/orsemidynamic,continuous,unknown.
0 Satisficing:deliberatinglongenoughtocomeupwithananswerthatis goodenough.0 ‘Good’iscontext‐dependent,i.e.withrespecttoapurpose.
0 AnytimeAlgorithms:thereisalways anoutput,whichbecomesbetterovertime.
0 Boundedrationality:formsofrationalbehaviorthatadheretotheconstraintsofsatisficing.
0 Boundedoptimality:thebestalgorithmgiventhecomputationalresourceconstraints.
Meta‐Cognition0 Decision‐TheoreticMetareasoning:decidingwhichcomputationstoperform(inwhatorder)andwhichnot.
0 Computationsarecharacterizedbycostsandbenefits:0 Cost:time,memory,andknowledgeinputneeded.0 Benefit:theprojectedqualityimprovementofthesystem’sbehaviorduetothecomputation.
0 Computationordering:anearliercomputation’sbenefitmaybetheknowledgeinputtolatercomputations.
0 ReflectiveArchitecture:combiningenvironment stateandcomputationstate.Anagents’reasoningprocessbecomespartoftheenvironment(whatisobserved).
MultiagentSystems0 Cooperation0 Competition0 Swarmintelligence:performancemeasureappliedtocollectivebehavior.
0 Decentralizedrepresentation0 Emergentbehavior
0 Weakemergence:thequalitiesofthesystemarereducibletothesystem'sconstituentparts.
0 Strongemergence:e.g.qualia.0 Theconceptsofutilityandrationalitychange!
0 Whatisrationalfortheswarmisnot thesumofwhatisrationalforallindividuals.
Prisoner’sdilemmaPrisonerBsilent PrisonerBbetray
Prisoner Asilent A:1 day,B: 1day A:10year,B:0Prisoner Abetray A:0,B:10years A:9years,B:9years
Twosuspectsarearrested.Ifonetestifiesagainsttheother(betray)andtheotherremainssilent,thebetrayergoesfreeandthesilentaccomplicereceivesthefull10‐yearsentence.Ifbothremainsilent,bothprisonersaresentencedtoonly1dayfornotcooperatingwiththeinvestigation.Ifeachbetrays theother,eachreceivesa9‐yearsentence.Howshouldtheprisonersact?• Nomatterwhattheotherplayerdoes,a playerwillalwaysgainagreaterpayoffbyplayingbetray.
• Sinceinany situationbetrayingismorebeneficialthanremainingsilent,all rationalplayerswillbetray.
ModernSystemsandResults
AutonomousDriver0 DARPAGrandChallenge:competitionforlongdistance,driverlessvehicles.
0 Goal:making1/3ofthemilitarygroundunitsautonomous.
0 2005,STANLEY:driverlessroboticcarwinstheDARPAGrandChallenge,212kmoff‐roadcourse.
0 2006,BOSS:driverlessroboticcarinurbanarea.
AutonomousPlanning0 2000,RemoteAgent:on‐boardautonomousplanning,schedulingoperationsforspacecraft.NASA.
0 2004,MAPGEN:NASA’sMarsExplorationRovers.0 2008,MEXAR2,EuropeanSpaceAgency’sMarsExpress.
ComputationalLinguistics0 Speechrecognitionanddialoguehandlingincallcenters
0 AutomaticTranslation0 Hands‐freecomputing0 Speech‐to‐text0 Speakeridentification0 AI’smaininterestinthe1960’s.
Games
Chess0 1997,DeepBlue(IBM):thefirstcomputertobeattheworldchampioninchess,3.5‐2.5.0 “Thebrain’slaststand.”[Newsweek]0 IBM’sstockincreasedby$18.000.000.000.
0 2004,Hydra defeatsworldchampionPonomariov 2‐0.0 Elo rating2850‐3000,higherthanthatofanyhuman.
0 2007,Rybka defeatsseveralgrandmasters,evenwhengivingthemcertainadvantages.
Checkers: 1994,Chinook becomestheworldchampion.Go:MoGo,stillperformsatadvancedamateurlevel.0 Thereisstillworktodoonsomegames.
AutomaticClassification0 Patternrecognition0 Discoveringcomplicatedinteractions:e.g.druguse,medicalimaging.
0 OCR0 Handwritingrecognition0 Biometricidentification0 Creditcardusage0 Documentclassification
0 Classifying1.000.000.000spammessageseveryday.0 Search
Logisticsplanning0 1991,DART (DynamicAnalysisandReplanning Tool)scheduledtransportationduringthePersianGulfcrisis.0 Startingpoints,destinations,routes,conflictresolution.0 Over50.000vehicles,cargo,people.0 AccordingtoDARPA,thissystemalonepaidback30yearsofinvestmentinAI.
RoboticsToys:0 ASIMO0 1997‐present,RoboCup0 TOPIO,tabletennis
Practicalapplications:0 IndustrialRobotics0 2.000.000Roombas soldbyiRobotcorporation!
0 Roboticvacuumcleaners…
NeurologicalSimulation0 BlueBrainProject:Aneurologicallyrealisticmodelofneurons.
0 BlueGenesupercomputer0 NEURONsoftware0 2007,simulatingarat’sneocorticalcolumn(functionalpartoftheneocortex).
0 2009,directorHenryMarkram announcedtobuildahumanbrainin10yearstime.0 ThinkofwhatyoulearnedaboutthehistoryofAI.WhatiswrongwithMarkram’s announcement?
