1,164 research outputs found
Spoken content retrieval: A survey of techniques and technologies
Speech media, that is, digital audio and video containing spoken content, has blossomed in recent years. Large collections are accruing on the Internet as well as in private and enterprise settings. This growth has motivated extensive research on techniques and technologies that facilitate reliable indexing and retrieval. Spoken content retrieval (SCR) requires the combination of audio and speech processing technologies with methods from information retrieval (IR). SCR research initially investigated planned speech structured in document-like units, but has subsequently shifted focus to more informal spoken content produced spontaneously, outside of the studio and in conversational settings. This survey provides an overview of the field of SCR encompassing component technologies, the relationship of SCR to text IR and automatic speech recognition and user interaction issues. It is aimed at researchers with backgrounds in speech technology or IR who are seeking deeper insight on how these fields are integrated to support research and development, thus addressing the core challenges of SCR
Improving Searchability of Automatically Transcribed Lectures Through Dynamic Language Modelling
Recording university lectures through lecture capture systems is increasingly common.
However, a single continuous audio recording is often unhelpful for users, who may wish
to navigate quickly to a particular part of a lecture, or locate a specific lecture within a set
of recordings.
A transcript of the recording can enable faster navigation and searching. Automatic speech
recognition (ASR) technologies may be used to create automated transcripts, to avoid the
significant time and cost involved in manual transcription.
Low accuracy of ASR-generated transcripts may however limit their usefulness. In
particular, ASR systems optimized for general speech recognition may not recognize the
many technical or discipline-specific words occurring in university lectures. To improve
the usefulness of ASR transcripts for the purposes of information retrieval (search) and
navigating within recordings, the lexicon and language model used by the ASR engine may
be dynamically adapted for the topic of each lecture.
A prototype is presented which uses the English Wikipedia as a semantically dense, large
language corpus to generate a custom lexicon and language model for each lecture from a
small set of keywords. Two strategies for extracting a topic-specific subset of Wikipedia
articles are investigated: a naïve crawler which follows all article links from a set of seed
articles produced by a Wikipedia search from the initial keywords, and a refinement which
follows only links to articles sufficiently similar to the parent article. Pair-wise article
similarity is computed from a pre-computed vector space model of Wikipedia article term
scores generated using latent semantic indexing.
The CMU Sphinx4 ASR engine is used to generate transcripts from thirteen recorded
lectures from Open Yale Courses, using the English HUB4 language model as a reference
and the two topic-specific language models generated for each lecture from Wikipedia
Generating indicative-informative summaries with SumUM
We present and evaluate SumUM, a text summarization system that takes a raw technical text as input and produces an indicative informative summary. The indicative part of the summary identifies the topics of the document, and the informative part elaborates on some of these topics according to the reader's interest. SumUM motivates the topics, describes entities, and defines concepts. It is a first step for exploring the issue of dynamic summarization. This is accomplished through a process of shallow syntactic and semantic analysis, concept identification, and text regeneration. Our method was developed through the study of a corpus of abstracts written by professional abstractors. Relying on human judgment, we have evaluated indicativeness, informativeness, and text acceptability of the automatic summaries. The results thus far indicate good performance when compared with other summarization technologies
Improving searchability of automatically transcribed lectures through dynamic language modelling
Recording university lectures through lecture capture systems is increasingly common. However, a single continuous audio recording is often unhelpful for users, who may wish to navigate quickly to a particular part of a lecture, or locate a specific lecture within a set of recordings.
A transcript of the recording can enable faster navigation and searching. Automatic speech recognition (ASR) technologies may be used to create automated transcripts, to avoid the significant time and cost involved in manual transcription.
Low accuracy of ASR-generated transcripts may however limit their usefulness. In particular, ASR systems optimized for general speech recognition may not recognize the many technical or discipline-specific words occurring in university lectures. To improve the usefulness of ASR transcripts for the purposes of information retrieval (search) and navigating within recordings, the lexicon and language model used by the ASR engine may be dynamically adapted for the topic of each lecture.
A prototype is presented which uses the English Wikipedia as a semantically dense, large language corpus to generate a custom lexicon and language model for each lecture from a small set of keywords. Two strategies for extracting a topic-specific subset of Wikipedia articles are investigated: a naïve crawler which follows all article links from a set of seed articles produced by a Wikipedia search from the initial keywords, and a refinement which follows only links to articles sufficiently similar to the parent article. Pair-wise article similarity is computed from a pre-computed vector space model of Wikipedia article term scores generated using latent semantic indexing.
The CMU Sphinx4 ASR engine is used to generate transcripts from thirteen recorded lectures from Open Yale Courses, using the English HUB4 language model as a reference and the two topic-specific language models generated for each lecture from Wikipedia.
Three standard metrics – Perplexity, Word Error Rate and Word Correct Rate – are used to evaluate the extent to which the adapted language models improve the searchability of the resulting transcripts, and in particular improve the recognition of specialist words. Ranked Word Correct Rate is proposed as a new metric better aligned with the goals of improving transcript searchability and specialist word recognition.
Analysis of recognition performance shows that the language models derived using the similarity-based Wikipedia crawler outperform models created using the naïve crawler, and that transcripts using similarity-based language models have better perplexity and Ranked Word Correct Rate scores than those created using the HUB4 language model, but worse Word Error Rates.
It is concluded that English Wikipedia may successfully be used as a language resource for unsupervised topic adaptation of language models to improve recognition performance for better searchability of lecture recording transcripts, although possibly at the expense of other attributes such as readability
NLP Driven Models for Automatically Generating Survey Articles for Scientific Topics.
This thesis presents new methods that use natural language processing (NLP) driven models for summarizing research in scientific fields. Given a topic query in the form of a text string, we present methods for finding research articles relevant to the topic as well as summarization algorithms that use lexical and discourse information present in the text of these articles to generate coherent and readable extractive summaries of past research on the topic. In addition to summarizing prior research, good survey articles should also forecast future trends. With this motivation, we present work on forecasting future impact of scientific publications using NLP driven features.PhDComputer Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113407/1/rahuljha_1.pd
An improved method for text summarization using lexical chains
This work is directed toward the creation of a system for automatically sum-marizing documents by extracting selected sentences. Several heuristics including position, cue words, and title words are used in conjunction with lexical chain in-formation to create a salience function that is used to rank sentences for extraction. Compiler technology, including the Flex and Bison tools, is used to create the AutoExtract summarizer that extracts and combines this information from the raw text. The WordNet database is used for the creation of the lexical chains. The AutoExtract summarizer performed better than the Microsoft Word97 AutoSummarize tool and the Sinope commercial summarizer in tests against ideal extracts and in tests judged by humans
LiDom builder: Automatising the construction of multilingual domain modules
136 p.Laburpena Lan honetan LiDOM Builder tresnaren analisi, diseinu eta ebaluazioa aurkezten dira. Teknologian oinarritutako hezkuntzarako tresnen Domeinu Modulu Eleaniztunak testuliburu elektronikoetatik era automatikoan erauztea ahalbidetzen du LiDOM Builderek. Ezagutza eskuratzeko, Hizkuntzaren Prozesamendurako eta Ikaste Automatikorako teknikekin batera, hainbat baliabide eleaniztun erabiltzen ditu, besteak beste, Wikipedia eta WordNet.Domeinu Modulu Elebakarretik Domeinu Modulu Eleaniztunerako bidean, LiDOM Builder tresna DOM-Sortze ingurunearen (Larrañaga, 2012; Larrañaga et al., 2014) bilakaera dela esan genezake. Horretarako, LiDOM Builderek domeinua ikuspegi eleaniztun batetik adieraztea ahalbidetzen duen mekanismoa dakar. Domeinu Modulu Eleaniztunak bi maila ezberdinetako ezagutza jasotzen du: Ikaste Domeinuaren Ontologia (IDO), non hizkuntza ezberdinetan etiketatutako topikoak eta hauen arteko erlazio pedagogikoak jasotzen baitira, eta Ikaste Objektuak (IO), hau da, metadatuekin etiketatutako baliabide didaktikoen bilduma, hizkuntza horietan. LiDOM Builderek onartutako hizkuntza guztietan domeinuaren topikoak adierazteko aukera ematen du. Topiko bakoitza lotuta dago dagokion hizkuntzako bere etiketa baliokidearekin. Gainera, IOak deskribatzeko metadatu aberastuak erabiltzen ditu hizkuntza desberdinetan parekideak diren baliabide didaktikoak lotzeko.LiDOM Builderen, hasiera batean, domeinu-modulua hizkuntza jakin batean idatzitako dokumentu batetik erauziko da eta, baliabide eleaniztunak erabiliko dira, gerora, bai topikoak bai IOak beste hizkuntzetan ere lortzeko. Lan honetan, Ingelesez idatzitako liburuek osatuko dute informazio-iturri nagusia bai doitze-prozesuan bai ebaluazio-prozesuan. Zehazki, honako testuliburu hauek erabili dira: Principles of Object Oriented Programming (Wong and Nguyen, 2010), Introduction to Astronomy (Morison, 2008) eta Introduction to Molecular Biology (Raineri, 2010). Baliabide eleaniztunei dagokienez, Wikipedia, WordNet eta Wikipediatik erauzitako beste hainbat ezagutza-base erabili dira. Testuliburuetatik Domeinu Modulu Eleaniztunak eraikitzeko, LiDOM Builder hiru modulu nagusitan oinarritzen da: LiTeWi eta LiReWi moduluak IDO eleaniztuna eraikitzeaz arduratuko dira eta LiLoWi, aldiz, IO eleaniztunak eraikitzeaz. Jarraian, aipatutako modulu bakoitza xehetasun gehiagorekin azaltzen da.¿ LiTeWi (Conde et al., 2015) moduluak, edozein ikaste-domeinutako testuliburu batetik abiatuta, Hezkuntzarako Ontologia bati dagozkion hainbat termino eleaniztun identifikatuko ditu, hala nola TF-IDF, KP-Miner, CValue eta Shallow Parsing Grammar. Hori lortzeko, gainbegiratu gabeko datu-erauzketa teknikez eta Wikipediaz baliatzen da. Ontologiako topikoak erauzteak LiTeWi-n hiru urrats ditu: lehenik hautagai diren terminoen erauzketa; bigarrenik, lortutako terminoen konbinatzea eta fintzea azken termino zerrenda osatuz; eta azkenik, zerrendako terminoak beste hizkuntzetara mapatzea Wikipedia baliatuz.¿ LiReWi (Conde et al., onartzeko) moduluak Hezkuntzarako Ontologia erlazio pedagogikoez aberastuko du, beti ere testuliburua abiapuntu gisa erabilita. Lau motatako erlazio pedagogikoak erauziko ditu (isA, partOf, prerequisite eta pedagogicallyClose) hainbat teknika eta ezagutza-base konbinatuz. Ezagutza-baseen artean Wikipedia, WordNet, WikiTaxonomy, WibiTaxonomy eta WikiRelations daude. LiReWi-k ere hiru urrats emango ditu erlazioak lortzeko: hasteko, ontologiako topikoak erlazioak erauzteko erabiliko diren ezagutza-base desberdinekin mapatuko ditu; gero, hainbat erlazio-erauzle, bakoitza teknika desberdin batean oinarritzen dena, exekutatuko ditu konkurrenteki erlazio hautagaiak erauzteko; eta, bukatzeko, lortutako emaitza guztiak konbinatu eta iragaziko ditu erlazio pedagogikoen azken multzoa lortuz. Gainera, DOM-Sortzetik LiDOM Buildererako trantsizioan, tesi honetan hobetu egin dira dokumentuen indizeetatik erauzitako isA eta partOf erlazioak, Wikipedia baliabide gehigarri bezala erabilita (Conde et al., 2014).¿ LiLoWi moduluak IOak -batzuk eleaniztunak- erauziko ditu, abiapuntuko testuliburutik ez ezik Wikipedia edo WordNet bezalako ezagutza-baseetatik ere. IDO ontologiako topiko bakoitza Wikipedia eta WordNet-ekin mapatu ostean, LiLoWi-k baliabide didaktikoak erauziko ditu hainbat IO erauzlez baliatuz.IO erauzketa-prozesuan, DOM-Sortzetik LiDOM Buildereko bidean, eta Wikipedia eta WordNet erabili aurretik, ingelesa hizkuntza ere gehitu eta ebaluatu da (Conde et al., 2012).LiDOM Builderen ebaluaziori dagokionez, modulu bakoitza bere aldetik testatua eta ebaluatua izan da bai Gold-standard teknika bai aditu-ebaluazioa baliatuz. Gainera, Wikipedia eta WordNet ezagutza-baseen integrazioak IOen erauzketari ekarri dion hobekuntza ere ebaluatu da. Esan genezake kasu guztietan lortu diren emaitzak oso onak direla.Bukatzeko, eta laburpen gisa, lau dira LiDOM Builderek Domeinu Modulu Eleaniztunaren arloari egin dizkion ekarpen nagusiak:¿ Domeinu Modulu Eleaniztunak adierazteko mekanismo egokia.¿ LiTeWiren garapena. Testuliburuetatik Hezkuntzarako Ontologietarako terminologia eleaniztuna erauztea ahalbidetzen du modulu honek. Ingelesa eta Gaztelera hizkuntzentzako termino-erauzlea eskura dago https://github.com/Neuw84/LiTe URLan.¿ LiReWiren garapena. Testuliburuetatik Hezkuntzarako Ontologietarako erlazio pedagogikoak erauztea ahalbidetzen du modulu honek. Erabiltzen duen Wikipedia/WordNet mapatzailea eskura dago https://github.com/Neuw84/Wikipedia2WordNet URLan.¿ LiLoWiren garapena. Testuliburua eta Wikipedia eta WordNet ezagutza-baseak erabilita IO eleaniztunak erauztea ahalbidetzen du modulu honek
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XIP Dashboard: visual analytics from automated rhetorical parsing of scientific metadiscourse
A key competency that we seek to build in learners is a critical
mind, i.e. ability to engage with the ideas in the literature, and to identify when significant claims are being made in articles. The ability to decode such moves in texts is essential, as is the ability to make such moves in one’s own writing. Computational techniques for extracting them are becoming available, using Natural Language Processing (NLP) tuned to recognize the rhetorical signals that authors use when making a significant scholarly move. After reviewing related NLP work, we introduce the Xerox Incremental Parser (XIP), note previous work to render its output, and then motivate the design of the XIP Dashboard, a set of visual analytics modules built on XIP output, using the LAK/EDM open dataset as a test corpus. We report preliminary user reactions to a paper prototype of such a novel dashboard, describe the visualizations implemented to date, and present user scenarios for learners, educators and researchers. We conclude with a summary of ongoing design refinements, potential platform integrations, and questions that need to be investigated through end-user evaluations
Accessing spoken interaction through dialogue processing [online]
Zusammenfassung
Unser Leben, unsere Leistungen und unsere Umgebung, alles wird
derzeit durch Schriftsprache dokumentiert. Die rasante
Fortentwicklung der technischen Möglichkeiten Audio, Bilder und
Video aufzunehmen, abzuspeichern und wiederzugeben kann genutzt
werden um die schriftliche Dokumentation von menschlicher
Kommunikation, zum Beispiel Meetings, zu unterstützen, zu
ergänzen oder gar zu ersetzen. Diese neuen Technologien können
uns in die Lage versetzen Information aufzunehmen, die
anderweitig verloren gehen, die Kosten der Dokumentation zu
senken und hochwertige Dokumente mit audiovisuellem Material
anzureichern. Die Indizierung solcher Aufnahmen stellt die
Kerntechnologie dar um dieses Potential auszuschöpfen. Diese
Arbeit stellt effektive Alternativen zu schlüsselwortbasierten
Indizes vor, die Suchraumeinschränkungen bewirken und teilweise
mit einfachen Mitteln zu berechnen sind.
Die Indizierung von Sprachdokumenten kann auf verschiedenen
Ebenen erfolgen: Ein Dokument gehört stilistisch einer
bestimmten Datenbasis an, welche durch sehr einfache Merkmale
bei hoher Genauigkeit automatisch bestimmt werden kann.
Durch diese Art von Klassifikation kann eine Reduktion des
Suchraumes um einen Faktor der Größenordnung 410 erfolgen. Die
Anwendung von thematischen Merkmalen zur Textklassifikation
bei einer Nachrichtendatenbank resultiert in einer Reduktion um
einen Faktor 18. Da Sprachdokumente sehr lang sein können müssen
sie in thematische Segmente unterteilt werden. Ein neuer
probabilistischer Ansatz sowie neue Merkmale (Sprecherinitia
tive und Stil) liefern vergleichbare oder bessere Resultate als
traditionelle schlüsselwortbasierte Ansätze. Diese thematische
Segmente können durch die vorherrschende Aktivität
charakterisiert werden (erzählen, diskutieren, planen, ...),
die durch ein neuronales Netz detektiert werden kann. Die
Detektionsraten sind allerdings begrenzt da auch Menschen
diese Aktivitäten nur ungenau bestimmen. Eine maximale
Reduktion des Suchraumes um den Faktor 6 ist bei den verwendeten
Daten theoretisch möglich. Eine thematische Klassifikation
dieser Segmente wurde ebenfalls auf einer Datenbasis
durchgeführt, die Detektionsraten für diesen Index sind jedoch
gering.
Auf der Ebene der einzelnen Äußerungen können Dialogakte wie
Aussagen, Fragen, Rückmeldungen (aha, ach ja, echt?, ...) usw.
mit einem diskriminativ trainierten Hidden Markov Model erkannt
werden. Dieses Verfahren kann um die Erkennung von kurzen Folgen
wie Frage/AntwortSpielen erweitert werden (Dialogspiele).
Dialogakte und spiele können eingesetzt werden um
Klassifikatoren für globale Sprechstile zu bauen. Ebenso
könnte ein Benutzer sich an eine bestimmte Dialogaktsequenz
erinnern und versuchen, diese in einer grafischen
Repräsentation wiederzufinden.
In einer Studie mit sehr pessimistischen Annahmen konnten
Benutzer eines aus vier ähnlichen und gleichwahrscheinlichen
Gesprächen mit einer Genauigkeit von ~ 43% durch eine graphische
Repräsentation von Aktivität bestimmt.
Dialogakte könnte in diesem Szenario ebenso nützlich sein, die
Benutzerstudie konnte aufgrund der geringen Datenmenge darüber
keinen endgültigen Aufschluß geben. Die Studie konnte allerdings
für detailierte Basismerkmale wie Formalität und
Sprecheridentität keinen Effekt zeigen.
Abstract
Written language is one of our primary means for documenting our
lives, achievements, and environment. Our capabilities to
record, store and retrieve audio, still pictures, and video are
undergoing a revolution and may support, supplement or even
replace written documentation. This technology enables us to
record information that would otherwise be lost, lower the cost
of documentation and enhance highquality documents with
original audiovisual material.
The indexing of the audio material is the key technology to
realize those benefits. This work presents effective
alternatives to keyword based indices which restrict the search
space and may in part be calculated with very limited resources.
Indexing speech documents can be done at a various levels:
Stylistically a document belongs to a certain database which can
be determined automatically with high accuracy using very simple
features. The resulting factor in search space reduction is in
the order of 410 while topic classification yielded a factor
of 18 in a news domain.
Since documents can be very long they need to be segmented into
topical regions. A new probabilistic segmentation framework as
well as new features (speaker initiative and style) prove to be
very effective compared to traditional keyword based methods. At
the topical segment level activities (storytelling, discussing,
planning, ...) can be detected using a machine learning approach
with limited accuracy; however even human annotators do not
annotate them very reliably. A maximum search space reduction
factor of 6 is theoretically possible on the databases used. A
topical classification of these regions has been attempted
on one database, the detection accuracy for that index, however,
was very low.
At the utterance level dialogue acts such as statements,
questions, backchannels (aha, yeah, ...), etc. are being
recognized using a novel discriminatively trained HMM procedure.
The procedure can be extended to recognize short sequences such
as question/answer pairs, so called dialogue games.
Dialog acts and games are useful for building classifiers for
speaking style. Similarily a user may remember a certain dialog
act sequence and may search for it in a graphical
representation.
In a study with very pessimistic assumptions users are able to
pick one out of four similar and equiprobable meetings correctly
with an accuracy ~ 43% using graphical activity information.
Dialogue acts may be useful in this situation as well but the
sample size did not allow to draw final conclusions. However the
user study fails to show any effect for detailed basic features
such as formality or speaker identity
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