Alex Dialogue Systems Framework Documentation

153 Pages·2016·0.48 MB·English

Alex Dialogue Systems Framework
Documentation
Release 0.1
2012-2013, UFAL-DSG, MFF, CUNI, CZ and other contributors
June23,2016

Contents
1 Contents 3
1.1 Indexofmanuallywritteninsourcecodetreedocumentation. . . . . . . . . . . . . . . . . . . . . . 3
2 Alexmodules 33
2.1 alexpackage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3 Indicesandtables 119
4 Howtowritedocumentation 121
Bibliography 123
PythonModuleIndex 125
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AlexDialogueSystemsFrameworkDocumentation,Release0.1
Alex Dialogue Systems Framework or simply Alex is a set of algorithms, classes, and tools to facilitate building
spokendialoguesystems.
Contents 1
AlexDialogueSystemsFrameworkDocumentation,Release0.1
2 Contents
1
CHAPTER
Contents
1.1 Index of manually written in source code tree documentation
1.1.1 Building a voice activity detector (VAD)
Thistextdescribedhowtobuildavoiceactivitydetector(VAD)forAlex. ThisworkbuildsmultilingualVAD.That
meansthatwedonothaveVADsforindividuallanguagesbutratheronlyone.ItappearsthatNNVADhasthecapacity
todistinguishbetweennon-speechandspeechinanylanguage.
As of now, we use VAD based on neural networks (NNs) implemented in the Theano toolkit. The main advantage
thatthesamecodecanefficientlyrunbothCPUsandGPUsandTheanoimplementsautomaticderivations. Automatic
derivationsisveryusefulespeciallywhengradientdescendtechniques,suchasstochasticgradientdescent,areused
formodelparametersoptimisation.
OldGMMcodeisstillpresentbutitmaynotworkanditsperformancewouldbesignificantlyworsethatofthecurrent
NNimplementation.
ExperimentsandthenotesfortheNNVAD
• testingisperformedonrandomlysampleddatapoints(20%)fromtheentireset
• L2regularisationmustbeverysmall,inadditionitdoesnothelpmuch
• insteadofMFCC,weusemel-filterbankscoefficientsonly. Itlooksliketheperformanceisthesameoreven
better
• asof2014-09-19thebestcompromisebetweenthemodelcomplexityandtheperformanceappearstobe.
– 30previousframes
– 15nextframes
– 512hiddenunits
– 4hiddenlayers
– tanhhiddenlayeractivation
– 4xamplificationofthecentralframecomparedtoouterframes
– discriminativepre-training
– giventhissetupwegetabout95.3%frameaccuracyonabout27millionofalldata
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Data
data_vad_sil # a directory with only silence, noise data and its mlf file
data_voip_cs # a directory where CS data reside and its MLF (phoneme alignment)
data_voip_en # a directory where EN data reside and its MLF (phoneme alignment)
model_voip # a directory where all the resulting models are stored.
Scripts
upload_models.sh # uploads all available models in ``model_voip`` onto the Alex online update server
train_voip_nn_theano_sds_mfcc.py # this is the main trainign script, see its help for more details
bulk_train_nn_theano_mbo_31M_sgd.sh # script with curently ``optimal`` setting for VAD
Comments
Tosavesometimeespeciallyformultipleexperimentsonthesamedata,westorepreprocessedspeechparametrisation.
Thespeechparametrisationisstoredbecauseittakesabout7hourstoproduce.However,ittakesonly1minutetoload
from a disk file. The model_voip directory stores this speech parametrisation in *.npc files. There fore if new
dataisadded, thentheseNPCfilesmustbedeleted. IftherearenoNPCfilesthentheyareautomaticallygenerated
fromtheavailableWAVfiles.
The data_voip_{cs,en} alignment files (mlf files) can be trained using scripts alex/alex/tools/htk or
alex/alex/tools/kaldi.Seethetrain_voip_{cs,en}.shscriptsinoneofthedirectories.Notethatthe
Kaldiscriptsfirststorealignmentinctmformatandlaterconvertsittomlfformat.
1.1.2 Building of acoustic models using HTK
In this document, we describe building of acoustic models using the HTK toolkit using the provided scripts. These
acousticmodelscanbeusedwiththeOpenJuliusASRdecoder.
Webuildadifferentacousticmodelforaeachlanguageandacousticconditionpair–LANG_RCOND.Atthistime,we
providetwosetsofscriptsforbuildingEnglishandCzechacousticmodelsusingtheVOIPdata.
Ingeneral,thescriptscanbedescribedforthelanguageandacousticconditionLANG_RCONDasfollows:
./env_LANG_RCOND.sh - includes all necessary training parameters: e.g. the train and test data directories,
training options including cross word or word internal triphones, language model weights
./train_LANG_RCOND.sh - performs the training of acoustic models
./nohup_train_LANG_RCOND.sh - calls the training script using nohup and redirecting the output into the .log_* file
The training process stores some configuration files, the intermediate files, and final models and evaluations in the
model_LANG_RCONDdirectory:
model_LANG_RCOND/config - config contains the language or recording specific configuration files
model_LANG_RCOND/temp
model_LANG_RCOND/log
model_LANG_RCOND/train
model_LANG_RCOND/test
Trainingmodelsforanewlanguage
ScriptsforCzechandEnglisharealreadycreated. Ifyouneedmodelsforanewlanguage,youcanstartbycopying
alltheoriginalscriptsandrenamingthemsoastoreflectthenewlanguageintheirname(substitute_enor_cswith
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yournewlanguagecode). Youcandothisbyissuingthefollowingcommand(weassume$OLDLANGissettoeither
enorcsand$NEWLANGtoyournewlanguagecode):
bash htk $ find . -name "*_$OLDLANG*" |
xargs -n1 bash -c "cp -rvn \$1 \${1/_$OLDLANG/_$NEWLANG}" bash
Havingdonethis,referencestothenewfiles’nameshavetobeupdated,too:
bash htk $ find . -name "*_$NEWLANG*" -type f -execdir \
sed --in-place s/_$OLDLANG/_$NEWLANG/g '{}' \;
Furthermore,youneedtoadjustlanguage-specificresourcestothenewlanguageinthefollowingways:
htk/model_voip_$NEWLANG/monophones0 Listallthephonestoberecognised,andthespecial
silphone.
htk/model_voip_$NEWLANG/monophones1 Listallthephonestoberecognised,andthespecial
silandspphones.
htk/model_voip_$NEWLANG/tree_ques.hed Specifyphoneticquestionstobeusedforbuild-
ingthedecisiontreeforphoneclustering(see[HTKBook],Section10.5).
htk/bin/PhoneticTranscriptionCS.pl You can start from this script or use a custom one.
Thegoalistoimplementtheorthography-to-phoneticsmappingtoobtainsequencesofphonesfrom
transcriptionsyouhave.
htk/common/cmudict.0.7aandhtk/common/cmudict.ext Thisisanalternativeapproach
tothepreviouspoint–insteadofprogrammingtheorthography-to-phoneticsmapping,youcanlist
itexplicitlyinapronouncingdictionary.
Dependingonthewayyouwanttoimplementthemapping,youwanttoset$OLDLANGtoeithercs
oren.
Tomakethescriptsworkwithyournewfiles,youwillhavetoupdatereferencestoscriptsyoucreated. Allscriptsare
storedinthehtk/bin,htk/common,andhtkdirectoriesasimmediatechildren,soyoucanmakethesubstitutions
onlyinthesefiles.
Creditsandthelicence
The scripts are based on the HTK Wall Street Journal Training Recipe written by Keith Vertanen
(http://www.keithv.com/software/htk/). His code is released under the new BSD licence. The licence note is at
http://www.keithv.com/software/htk/. Asaresultwecanre-licensethecodeundertheAPACHE2.0license.
Theresults
• totaltrainingdataforvoip_enisabout20hours
• totaltrainingdataforvoip_csisabout8hours
• mixtures-thereis16mixturesisslightlybetterthan8mixturesforvoip_en
• thereisnosignificantdifferenceinalignmentoftranscriptionswith-t150and-t250
• theJuliusASRperformanceisaboutthesameasofHDecode
• HDecodeworkswellwhencrosswordphonesaretrained,howeverthe-performanceofHVitedecreasessig-
nificantly
• when only word internal triphones are trained then the HDecode works, - however, its performance is worse
thantheHVitewithabigramLM
1.1. Indexofmanuallywritteninsourcecodetreedocumentation 5
AlexDialogueSystemsFrameworkDocumentation,Release0.1
• wordinternaltriphonesworkwellwithJuliusASR,donotforgetdisableCCD(itdoesnotneedcontexthandling
-thoughitstillusestriphones)
• thereisnotmuchgainusingthetrigramLMintheCaminfodomain(about1%)
1.1.3 Building a SLU for the PTIcs domain
Availabledata
Atthismoment,weonlyhavedatawhichwereautomaticallygeneratedusingourhandcraftedSLU(HDCSLU)parser
onthetranscribedaudio. Ingeneral,thequalityoftheautomaticannotationisverygood.
The data can be prepared using the prapare_data.py script. It assumes that there exist the indomain_data
directory with links to directories containing asr_transcribed.xml files. Then it uses these files to extract
transcriptionsandgenerateautomaticSLUannotationsusingthePTICSHDCSLUparserfromthehdc_slu.pyfile.
Thescriptgeneratesthefollowingfiles:
• *.trn: containsmanualtranscriptions
• *.trn.hdc.sem: containsautomaticannotationfromtranscriptionsusinghandcraftedSLU
• *.asr: containsASR1-bestresults
• *.asr.hdc.sem: containsautomaticannotationfrom1-bestASRusinghandcraftedSLU
• *.nbl: containsASRN-bestresults
• *.nbl.hdc.sem: containsautomaticannotationfromn-bestASRusinghandcraftedSLU
Thescriptaccepts--uniqparameterforfastgenerationofuniqueHDCSLUannotations.Thisisusefulwhentuning
theHDCSLU.
BuildingtheDAILogRegClassifiermodels
First,preparethedata. Linkthedirectorieswiththein-domaindataintotheindomain_datadirectory. Thenrun
thefollowingcommand:
./prepare_data.py
Second,trainandtestthemodels.
:: cd./dailogregclassifier
./train.py&&./test_trn.py&&./test_hdc.py&&./test_bootstrap_trn.py&&./test_bootsrap_hdc.py
Third,lookatthe*.scorefilesorcomputetheinterestingscoresbyrunning:
./print_scores.sh
Futurework
• ExploitASRLatticesinsteadoflongNBLists.
• ConditiontheSLUDialogueActItemdecodingontheprevioussystemdialogueact.
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