61A Lecture 37Friday, December 2Friday, December 2, 2011What is Computer Science?SystemsArtificial IntelligenceGraphicsSecurityNetworkingProgramming Languages...2Computer VisionPlanningRoboticsNatural Language Processing...Friday, December 2, 2011Machine Translation3I will do it laterTarget languageParallel corpus gives translation examplesYo lo haré de muy buen gradoI will do it gladlyDespués lo verasYou will see laterMachine translation system:Model of translationTarget language corpus gives examples of well-formed sentencesI will get to it laterSee you laterHe will do itYo lo haré despuésNOVEL SENTENCESource languageFriday, December 2, 2011The Syntactic Structure of Natural Language4VBMD VPVPNPSPRP ADVYo lo haré de muy buen gradoI will do it gladlyDespués lo verasYou will see laterPRPVBMD VPVPNPSPRPADVI will do it laterModel of translationYo lo haré despuésMachine translation system:SSADVADVParallel corpus gives translation examplesFriday, December 2, 2011A Translation System in 20 MinutesContext-free grammars as a model of language generationLarge-scale linguistic annotationsTree transformations5English Yoda-speakHelp you, I can! Yes! Mm!When 900 years old you reach, look as good, you will not. Hm.Friday, December 2, 2011A Context-Free Grammar Describes Generation6 S -> NP VPNP -> PRPPRP↓NP -> IVP -> VBVP -> VB PRPPRP -> you VB -> know VB -> help"Grammar""Lexicon"SNP VPPRP VB PRPI know youGrammar refinement↓VPPRP↓VP -> mePRP -> I↓NP↓VPFriday, December 2, 2011A Context-Free Grammar Describes Generation7 S -> NP VPNP -> PRPPRP -> IVP -> VBVP -> VB PRPPRP -> youVP -> MD VP VB -> know VB -> help MD -> can"Grammar""Lexicon"SNP VPPRPIA grammar can be learned from data (demo)canMDVPVB PRPhelp youFriday, December 2, 2011Left cornersLeft-Corner Parsing Builds Trees For Sentences8 S -> NP VPNP -> PRPPRP -> IVP -> VBVP -> VB PRPPRP -> you VB -> know VB -> help"Grammar""Lexicon"Siknow youNPPRPVBcomplete(VP, (VP (VB know)), 2)VPparse_next(S, 1)complete(S, (PRP i), 1)complete(S, (NP (PRP i)), 1)parse_next(VP, 2)complete(VP, (VB know), 2)complete(S, (S ...), 1)Friday, December 2, 2011Left-Corner Parsing Builds Trees For Sentences9 S -> NP VPNP -> PRPPRP -> IVP -> VBVP -> VB PRPPRP -> you VB -> know VB -> help"Grammar""Lexicon"SNPPRPVBiknow youVPPRPLeft cornerscomplete(VP, (VP (VB know) (PRP you)), 2)parse_next(S, 1)complete(S, (PRP i), 1)complete(S, (NP (PRP i)), 1)parse_next(VP, 2)complete(VP, (VB know), 2)complete(S, (S ...), 1)Friday, December 2,
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