Joint morphological-lexical language modeling for processing morphologically rich languages with application to dialectal Arabic

Language modeling for an inflected language such as Arabic poses new challenges for speech recognition and machine translation due to its rich morphology. Rich morphology results in large increases in out-of-vocabulary (OOV) rate and poor language model parameter estimation in the absence of large quantities of data. In this study, we present a joint morphological-lexical language model (JMLLM) that takes advantage of Arabic morphology. JMLLM combines morphological segments with the underlying lexical items and additional available information sources with regards to morphological segments and lexical items in a single joint model. Joint representation and modeling of morphological and lexical items reduces the OOV rate and provides smooth probability estimates while keeping the predictive power of whole words. Speech recognition and machine translation experiments in dialectal-Arabic show improvements over word and morpheme based trigram language models. We also show that as the tightness of integration between different information sources increases, both speech recognition and machine translation performances improve

Rapid Language Model Development Using External Resources for New Spoken Dialog Domains

This paper addresses a critical problem in deploying a spoken dialog system (SDS). One of the main bottlenecks of SDS deployment for a new domain is data sparseness in building a statistical language model. Our goal is to devise a method to efficiently build a reliable language model for a new SDS. We consider the worst yet quite common scenario where only a small amount (∼1.7K utterances) of domain specific data is available for the target domain. We present a new method that exploits external static text resources that are collected for other speech recognition tasks as well as dynamic text resources acquired from World Wide Web (WWW). We show that language models built using external resources can jointly be used with limited in–domain (baseline) language model to obtain significant improvements in speech recognition accuracy. Combining language models built using external resources with the in–domain language model provides over 20 % reduction in WER over the baseline in–domain language model. Equivalently, we achieve almost the same level of performance by having ten times as much in–domain data (17K utterances)

Convolutional neural network based triangular CRF for joint intent detection and slot filling,”

ABSTRACT We describe a joint model for intent detection and slot filling based on convolutional neural networks (CNN). The proposed architecture can be perceived as a neural network (NN) version of the triangular CRF model (TriCRF), in which the intent label and the slot sequence are modeled jointly and their dependencies are exploited. Our slot filling component is a globally normalized CRF style model, as opposed to left-toright models in recent NN based slot taggers. Its features are automatically extracted through CNN layers and shared by the intent model. We show that our slot model component generates state-of-the-art results, outperforming CRF significantly. Our joint model outperforms the standard TriCRF by 1% absolute for both intent and slot. On a number of other domains, our joint model achieves 0.7 -1%, and 0.9 -2.1% absolute gains over the independent modeling approach for intent and slot respectively