regular relation (of strings)

《regular relation (of strings)》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、Relation:likeafunction,butmultipleoutputsokRegular:finite-stateTransducer:automatonw/outputsb?a?aaaaa?Invertible?Closedundercomposition?RegularRelation(ofstrings)b:ba:aa:ea:cb:eb:b?:c?:a?:balittlepre-talkreviewCanweightthearcs:vs.a{}b{b}aaaaa{ac,aca,acab,acabc}Howtofindbestoutputs?F

2、oraaaaa?Forallinputsatonce?RegularRelation(ofstrings)b:ba:aa:ea:cb:eb:b?:c?:a?:balittlepre-talkreviewJasonEisnerU.ofRochesterAugust3,2000–COLING-SaarbrückenDirectionalConstraintEvaluationinOTSynopsis:FixingOT’sPowerConsensus:Phonology=regularrelationE.g.,compositionoflittlelocaladjustments

3、(=FSTs)Problem:Evenfinite-stateOTisworsethanthatGlobal“counting”(Frank&Satta1998)Problem:PhonologistswanttoaddevenmoreTrytocaptureiterativitybyGen.AlignmentconstraintsSolution:InOT,replacecountingbyiterativityEachconstraintdoesaniterativeoptimizationOutlineReviewofOptimalityTheoryThenew“dir

4、ectionalconstraints”ideaLinguistically:FitsthefactsbetterComputationally:RemovesexcesspowerFormalstuffTheproposalCompilationintofinite-statetransducersExpressivepowerofdirectionalconstraintsWhatIsOptimalityTheory?Prince&Smolensky(1993)AlternativetostepwisederivationStepwisewinnowingofcandid

5、atesetGenConstraint1Constraint2Constraint3input...outputsuchthatdifferentconstraintordersyielddifferentlanguagesFiltering,OT-styleconstraintwouldpreferA,butonlyallowedtobreaktieamongB,D,E««=candidateviolatesconstrainttwiceATroublesomeExampleInput:bantodiboHarmonyFaithfulnessban.to.di.bo«be

6、n.ti.do.bu«««««ban.ta.da.ba«««bon.to.do.bo««“Majorityassimilation”–impossiblewithFST--anddoesn’thappeninpractice!OutlineReviewofOptimalityTheoryThenew“directionalconstraints”ideaLinguistically:FitsthefactsbetterComputationally:RemovesexcesspowerFormalstuffTheproposalCompilationintofinite-s

7、tatetransducersExpressivepowerofdirectionalconstraintsAnArtificialExampleNoCodaban.to.di.bo«ban.ton.di.bo««ban.to.dim.bon«««ban.ton.dim.bon««««Candidateshave1,2,3,4violationsofNoCodaAnArtificialExampleCNoCodaban.to.di.bo««ban.ton.di.bo««ban.to.dim.bon«