102 research outputs found
The CALO meeting speech recognition and understanding system
ABSTRACT The CALO Meeting Assistant provides for distributed meeting capture, annotation, automatic transcription and semantic analysis of multi-party meetings, and is part of the larger CALO personal assistant system. This paper summarizes the CALO-MA architecture and its speech recognition and understanding components, which include realtime and offline speech transcription, dialog act segmentation and tagging, question-answer pair identification, action item recognition, and summarization
Automatic recognition of multiparty human interactions using dynamic Bayesian networks
Relating statistical machine learning approaches to the automatic analysis of multiparty
communicative events, such as meetings, is an ambitious research area. We
have investigated automatic meeting segmentation both in terms of “Meeting Actions”
and “Dialogue Acts”. Dialogue acts model the discourse structure at a fine
grained level highlighting individual speaker intentions. Group meeting actions describe
the same process at a coarse level, highlighting interactions between different
meeting participants and showing overall group intentions.
A framework based on probabilistic graphical models such as dynamic Bayesian
networks (DBNs) has been investigated for both tasks. Our first set of experiments
is concerned with the segmentation and structuring of meetings (recorded using
multiple cameras and microphones) into sequences of group meeting actions such
as monologue, discussion and presentation. We outline four families of multimodal
features based on speaker turns, lexical transcription, prosody, and visual motion
that are extracted from the raw audio and video recordings. We relate these lowlevel
multimodal features to complex group behaviours proposing a multistreammodelling
framework based on dynamic Bayesian networks. Later experiments are
concerned with the automatic recognition of Dialogue Acts (DAs) in multiparty
conversational speech. We present a joint generative approach based on a switching
DBN for DA recognition in which segmentation and classification of DAs are
carried out in parallel. This approach models a set of features, related to lexical
content and prosody, and incorporates a weighted interpolated factored language
model. In conjunction with this joint generative model, we have also investigated
the use of a discriminative approach, based on conditional random fields, to perform
a reclassification of the segmented DAs.
The DBN based approach yielded significant improvements when applied both
to the meeting action and the dialogue act recognition task. On both tasks, the DBN
framework provided an effective factorisation of the state-space and a flexible infrastructure
able to integrate a heterogeneous set of resources such as continuous
and discrete multimodal features, and statistical language models. Although our
experiments have been principally targeted on multiparty meetings; features, models,
and methodologies developed in this thesis can be employed for a wide range
of applications. Moreover both group meeting actions and DAs offer valuable insights about the current conversational context providing valuable cues and features
for several related research areas such as speaker addressing and focus of attention
modelling, automatic speech recognition and understanding, topic and decision detection
Dialogue Act Recognition via CRF-Attentive Structured Network
Dialogue Act Recognition (DAR) is a challenging problem in dialogue
interpretation, which aims to attach semantic labels to utterances and
characterize the speaker's intention. Currently, many existing approaches
formulate the DAR problem ranging from multi-classification to structured
prediction, which suffer from handcrafted feature extensions and attentive
contextual structural dependencies. In this paper, we consider the problem of
DAR from the viewpoint of extending richer Conditional Random Field (CRF)
structural dependencies without abandoning end-to-end training. We incorporate
hierarchical semantic inference with memory mechanism on the utterance
modeling. We then extend structured attention network to the linear-chain
conditional random field layer which takes into account both contextual
utterances and corresponding dialogue acts. The extensive experiments on two
major benchmark datasets Switchboard Dialogue Act (SWDA) and Meeting Recorder
Dialogue Act (MRDA) datasets show that our method achieves better performance
than other state-of-the-art solutions to the problem. It is a remarkable fact
that our method is nearly close to the human annotator's performance on SWDA
within 2% gap.Comment: 10 pages, 4figure
Reconocimiento de acto de diálogo secuencial para debates argumentativos árabes
Dialogue act recognition remains a primordial task that helps user to automatically identify participants’ intentions. In this paper, we propose a sequential approach consisting of segmentation followed by annotation process to identify dialogue acts within Arabic politic debates. To perform DA recognition, we used the CARD corpus labeled using the SADA annotation schema. Segmentation and annotation tasks were then carried out using Conditional Random Fields probabilistic models as they prove high performance in segmenting and labeling sequential data. Learning results are notably important for the segmentation task (F-score=97.9%) and relatively reliable within the annotation process (f-score=63.4%) given the complexity of identifying argumentative tags and the presence of disfluencies in spoken conversations.El reconocimiento del acto de diálogo sigue siendo una tarea primordial que ayuda al usuario a identificar automáticamente las intenciones de los participantes. En este documento, proponemos un enfoque secuencial que consiste en la segmentación seguida de un proceso de anotación para identificar actos de diálogo dentro de los debates políticos árabes. Para realizar el reconocimiento DA, utilizamos el corpus CARD etiquetado utilizando el esquema de anotación SADA. Las tareas de segmentación y anotación se llevaron a cabo utilizando modelos probabilísticos de Campos aleatorios condicionales, ya que demuestran un alto rendimiento en la segmentación y el etiquetado de datos secuenciales. Los resultados de aprendizaje son especialmente importantes para la tarea de segmentación (F-score = 97.9%) y relativamente confiables dentro del proceso de anotación (f-score = 63.4%) dada la complejidad de identificar etiquetas argumentativas y la presencia de disfluencias en las conversaciones habladas
Framework for Human Computer Interaction for Learning Dialogue Strategies using Controlled Natural Language in Information Systems
Spoken Language systems are going to have a tremendous impact in all
the real world applications, be it healthcare enquiry, public transportation
system or airline booking system maintaining the language ethnicity for
interaction among users across the globe. These system have the capability
of interacting with the user in di erent languages that the system
supports. Normally when a person interacts with another person there are
many non-verbal clues which guide the dialogue and all the utterances have
a contextual relationship, which manage the dialogue as its mixed by the
two speakers. Human Computer Interaction has a wide impact on the design
of the applications and has become one of the emerging interest area of
the researchers. All of us are witness to an explosive electronic revolution
where lots of gadgets and gizmo's have surrounded us, advanced not only
in power, design, applications but the ease of access or what we call user
friendly interfaces are designed that we can easily use and control all the
functionality of the devices. Since speech is one of the most intuitive form
of interaction that humans use. It provides potential bene ts such as handfree
access to machines, ergonomics and greater e ciency of interaction.
Yet, speech-based interfaces design has been an expert job for a long time.
Lot of research has been done in building real spoken Dialogue Systems
which can interact with humans using voice interactions and help in performing
various tasks as are done by humans. Last two decades have seen
utmost advanced research in the automatic speech recognition, dialogue
management, text to speech synthesis and Natural Language Processing
for various applications which have shown positive results. This dissertation
proposes to apply machine learning (ML) techniques to the problem
of optimizing the dialogue management strategy selection in the Spoken
Dialogue system prototype design. Although automatic speech recognition
and system initiated dialogues where the system expects an answer in the
form of `yes' or `no' have already been applied to Spoken Dialogue Systems(
SDS), no real attempt to use those techniques in order to design a
new system from scratch has been made. In this dissertation, we propose
some novel ideas in order to achieve the goal of easing the design of Spoken
Dialogue Systems and allow novices to have access to voice technologies.
A framework for simulating and evaluating dialogues and learning optimal
dialogue strategies in a controlled Natural Language is proposed. The simulation
process is based on a probabilistic description of a dialogue and
on the stochastic modelling of both arti cial NLP modules composing a
SDS and the user. This probabilistic model is based on a set of parameters
that can be tuned from the prior knowledge from the discourse or learned
from data. The evaluation is part of the simulation process and is based
on objective measures provided by each module. Finally, the simulation
environment is connected to a learning agent using the supplied evaluation
metrics as an objective function in order to generate an optimal behaviour
for the SDS
Extracting and using prosodic information for Turkish spoken language processing
Bu projede genel olarak, konuşulan dili (Türkçe) anlamada, konuşulan dilin bürünsel/ezgisel (prosodic) ve sözcüksel (lexical) özelliklerinin ortaya çıkarılması ve bu özelliklerin konuşulan dilin bilgisayarla otomatik olarak işlenmesinde kullanılması amaçlanmaktadır. Bu daha özel olarak, otomatik konuşma tanıyıcısının (ASR) çıkışına ilişkin cümle bölütleme işlevini içermektedir. Otomatik konuşma tanıma sistemlerinden çıkan yazılı metnin özellikle noktalama (punctuation), büyük küçük harf farklılıkları ve vurgu, tonlama, perde, durak gibi konuşmaya ilişkin temel bazı parametrelerden yoksun olması veya bu özellikleri kaybetmiş olması, özellikle anlamda farklılıklara yol açmaktadır. Bu çıktının zenginleştirilmesi (enrichment) başka bir deyiş ile bu özelliklerin tekrar geriye kazandırılması, bu metinlerin hem insanlar tarafından okunmasını ve doğru algılanmasını hem de makineler tarafından işlenmesini kolaylaştıracaktır. Bu projedeki amaç, bu zenginleştirme ve geri kazandırım işleminin dilin bürünsel özelliklerinden yararlanarak yapılmasıdır.The text which the output of the Automatic Speech Recognition (ASR) system lacks especially punctuation, differences in the capitalization and the parameters related to the speaking such as stress, tone, pitch, pause cause some differences in the meaning. Enrichment of this output or another words to gain this features back to the output will provide either reading and understanding of the humans or processing of the machines easily. The aim of this project is doing this enrichment and the process of gaining back by using the prosodic features of the spoken language. In this proposal, we would like to examine the extraction and use of prosodic information in addition to lexical features for spoken language processing of Turkish. Specifically, we would like to research the use of prosodic features for sentence segmentation of Turkish speech. Another outcome of the project is to obtain a database of prosodic features at the word and morpheme level, which can be used for other purposes such as morphological disambiguation or word sense disambiguation. Turkish is an agglutinative language. Thus, the text should be analyzed morphologically in order to determine the root forms and the suffixes of the words before further analysis. In the framework of this project, we also would like to examine the interaction of prosodic features with morphological information. The role of sentence segmentation is to detect sentence boundaries in the stream of words provided by the ASR module for further downstream processing. This is helpful for various language processing tasks, such as parsing, machine translation and question answering. We formulate sentence segmentation as a binary classification task. For each position between two consecutive words the system must decide if the position marks a boundary between two sentences or if the two neighboring words belong to the same sentence. The sentence segmentation process is established by combining the Hidden Event Language Models (HELMs) with discriminative classification methods. The HELM takes into account the sequence of words and the output discriminative classification methods such as decision tree that is based on prosodic features such as pause durations. The new approach combines the HELMs for exploiting lexical information, with maximum entropy and boosting classifiers that tightly integrate lexical, as well as prosodic, speaker change and syntactic features. The boostingbased classifier alone performs better than all the other classification schemes. When combined with a hidden event language model the improvement is even more pronounced.Publisher's Versio
Intention Detection Based on Siamese Neural Network With Triplet Loss
Understanding the user's intention is an essential task for the spoken language understanding (SLU) module in the dialogue system, which further illustrates vital information for managing and generating future action and response. In this paper, we propose a triplet training framework based on the multiclass classification approach to conduct the training for the intention detection task. Precisely, we utilize a Siamese neural network architecture with metric learning to construct a robust and discriminative utterance feature embedding model. We modified the RMCNN model and fine-tuned BERT model as Siamese encoders to train utterance triplets from different semantic aspects. The triplet loss can effectively distinguish the details of two input data by learning a mapping from sequence utterances to a compact Euclidean space. After generating the mapping, the intention detection task can be easily implemented using standard techniques with pre-trained embeddings as feature vectors. Besides, we use the fusion strategy to enhance utterance feature representation in the downstream of intention detection task. We conduct experiments on several benchmark datasets of intention detection task: Snips dataset, ATIS dataset, Facebook multilingual task-oriented datasets, Daily Dialogue dataset, and MRDA dataset. The results illustrate that the proposed method can effectively improve the recognition performance of these datasets and achieves new state-of-the-art results on single-turn task-oriented datasets (Snips dataset, Facebook dataset), and a multi-turn dataset (Daily Dialogue dataset)
Metadiscourse Tagging in Academic Lectures
This thesis presents a study into the nature and structure of academic lectures, with a special focus on metadiscourse phenomena. Metadiscourse refers to a set of linguistics expressions that signal specific discourse functions such as the Introduction: “Today we will talk about...” and Emphasising: “This is an important point”. These functions are important because they are part of lecturers’ strategies in understanding of what happens in a lecture. The knowledge of their presence and identity could serve as initial steps toward downstream applications that will require functional analysis of lecture content such as a browser for lectures archives, summarisation, or an automatic minute-taker for lectures. One challenging aspect for metadiscourse detection and classification is that the set of expressions are semi-fixed, meaning that different phrases can indicate the same function.
To that end a four-stage approach is developed to study metadiscourse in academic lectures. Firstly, a corpus of metadiscourse for academic lectures from Physics and Economics courses is built by adapting an existing scheme that describes functional-oriented metadiscourse categories. Second, because producing reference transcripts is a time-consuming task and prone to some errors due to the manual efforts required, an automatic speech recognition (ASR) system is built specifically to produce transcripts of lectures. Since the reference transcripts lack time-stamp information, an alignment system is applied to the reference to be able to evaluate the ASR system. Then, a model is developed using Support Vector Machines (SVMs) to classify metadiscourse tags using both textual and acoustical features. The results show that n-grams are the most inductive features for the task; however, due to data sparsity the model does not generalise for unseen n-grams. This limits its ability to solve the variation issue in metadiscourse expressions. Continuous Bag-of-Words (CBOW) provide a promising solution as this can capture both the syntactic and semantic similarities between words and thus is able to solve the generalisation issue. However, CBOW ignores the word order completely, something which is very important to be retained when classifying metadiscourse tags.
The final stage aims to address the issue of sequence modelling by developing a joint CBOW and Convolutional Neural Network (CNN) model. CNNs can work with continuous features such as word embedding in an elegant and robust fashion by producing a fixed-size feature vector that is able to identify indicative local information for the tagging task. The results show that metadiscourse tagging using CNNs outperforms the SVMs model significantly even on ASR outputs, owing to its ability to predict a sequence of words that is more representative for the task regardless of its position in the sentence. In addition, the inclusion of other features such as part-of-speech (POS) tags and prosodic cues improved the results further. These findings are consistent in both disciplines.
The final contribution in this thesis is to investigate the suitability of using metadiscourse tags as discourse features in the lecture structure segmentation model, despite the fact that the task is approached as a classification model and most of the state-of-art models are unsupervised. In general, the obtained results show remarkable improvements over the state-of-the-art models in both disciplines
Recognition and Understanding of Meetings Overview of the European AMI and AMIDA Projects
The AMI and AMIDA projects are concerned with the recognition and interpretation of multiparty (face-to-face and remote) meetings. Within these projects we have developed the following: (1) an infrastructure for recording meetings using multiple microphones and cameras; (2) a one hundred hour, manually annotated meeting corpus; (3) a number of techniques for indexing, and summarizing of meeting videos using automatic speech recognition and computer vision, and (4) a extensible framework for browsing, and searching of meeting videos. We give an overview of the various techniques developed in AMI (mainly involving face-to-face meetings), their integration into our meeting browser framework, and future plans for AMIDA (Augmented Multiparty Interaction with Distant Access), the follow-up project to AMI. Technical and business information related to these two projects can be found at www.amiproject.org, respectively on the Scientific and Business portals
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