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Item type:Publication, Improving neural machine translation with POS-tag features for low-resource language pairs(2022-08-01) ;Hlaing, Zar Zar ;Thu, Ye Kyaw ;Supnithi, ThepchaiNetisopakul, PonrudeeIntegrating linguistic features has been widely utilized in statistical machine translation (SMT) systems, resulting in improved translation quality. However, for low-resource languages such as Thai and Myanmar, the integration of linguistic features in neural machine translation (NMT) systems has yet to be implemented. In this study, we propose transformer-based NMT models (transformer, multi-source transformer, and shared-multi-source transformer models) using linguistic features for two-way translation of Thai-to-Myanmar, Myanmar-to-English, and Thai-to-English. Linguistic features such as part-of-speech (POS) tags or universal part-of-speech (UPOS) tags are added to each word on either the source or target side, or both the source and target sides, and the proposed models are conducted. The multi-source transformer and shared-multi-source transformer models take two inputs (i.e., string data and string data with POS tags) and produce string data or string data with POS tags. A transformer model that utilizes only word vectors was used as the first baseline model for comparison with the proposed models. The second baseline model, an Edit-Based Transformer with Repositioning (EDITOR) model, was also used to compare with our proposed models in addition to the baseline transformer model. The findings of the experiments show that adding linguistic features to the transformer-based models enhances the performance of a neural machine translation in low-resource language pairs. Moreover, the best translation results were yielded using shared-multi-source transformer models with linguistic features resulting in more significant Bilingual Evaluation Understudy (BLEU) scores and character n-gram F-score (chrF) scores than the baseline transformer and EDITOR models. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Graph-based Dependency Parser Building for Myanmar Language(2022-01-01) ;Hlaing, Zar Zar ;Thu, Ye Kyaw ;Supnithi, ThepchaiNetisopakul, PonrudeeExamining the relationships between words in a sentence to determine its grammatical structure is known as dependency parsing (DP). Based on this, a sentence is broken down into several components. The process is based on the concept that every linguistic component of a sentence has a direct relationship to one another. These relationships are called dependencies. Dependency parsing is one of the key steps in natural language processing (NLP) for several text mining approaches. As the dominant formalism for dependency parsing in recent years, Universal Dependencies (UD) have emerged. The various UD corpus and dependency parsers are publicly accessible for resource-rich languages. However, there are no publicly available resources for dependency parsing, especially for the low-resource language, Myanmar. Thus, we manually extended the existing small Myanmar UD corpus (i.e., myPOS UD corpus) as myPOS version 3.0 UD corpus to publish the extended Myanmar UD corpus as the publicly available resource. To evaluate the effects of the extended UD corpus versus the original UD corpus, we utilized the graph-based neural dependency parsing models, namely, jPTDP (joint POS tagging and dependency parsing) and UniParse (universal graph-based parsing), and the evaluation scores are measured in terms of unlabeled and labeled attachment scores: (UAS) and (LAS). We compared the accuracies of graph-based neural models based on the original and extended UD corpora. The experimental results showed that, compared to the original myPOS UD corpus, the extended myPOS version 3.0 UD corpus enhanced the accuracy of dependency parsing models. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Improving the state-of-the-art in Thai semantic similarity using distributional semantics and ontological information(2021-02-01) ;Netisopakul, Ponrudee ;Wohlgenannt, Gerhard ;Pulich, AlekseiHlaing, Zar ZarResearch into semantic similarity has a long history in lexical semantics, and it has applications in many natural language processing (NLP) tasks like word sense disambiguation or machine translation. The task of calculating semantic similarity is usually presented in the form of datasets which contain word pairs and a human-assigned similarity score. Algorithms are then evaluated by their ability to approximate the gold standard similarity scores. Many such datasets, with different characteristics, have been created for English language. Recently, four of those were transformed to Thai language versions, namely WordSim-353, SimLex-999, SemEval-2017-500, and R&G-65. Given those four datasets, in this work we aim to improve the previous baseline evaluations for Thai semantic similarity and solve challenges of unsegmented Asian languages (particularly the high fraction of out-of-vocabulary (OOV) dataset terms). To this end we apply and integrate different strategies to compute similarity, including traditional word-level embeddings, subword-unit embeddings, and ontological or hybrid sources like WordNet and ConceptNet. With our best model, which combines self-trained fastText subword embeddings with ConceptNet Numberbatch, we managed to raise the state-of-the-art, measured with the harmonic mean of Pearson on Spearman ρ, by a large margin from 0.356 to 0.688 for TH-WordSim-353, from 0.286 to 0.769 for TH-SemEval-500, from 0.397 to 0.717 for TH-SimLex-999, and from 0.505 to 0.901 for TWS-65. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, NECTEC’s Participation in WAT-2021(2021-01-01) ;Hlaing, Zar Zar ;Thu, Ye Kyaw ;Oo, Thazin Myint ;San, Mya EiUsanavasin, SasipornIn this paper, we report the experimental results of Machine Translation models conducted by a NECTEC team (Team-ID: NECTEC) for the WAT-2021 Myanmar-English translation task (Nakazawa et al., 2021). Basically, our models are based on neural methods for both directions of English-Myanmar and Myanmar-English language pairs. Most of the existing Neural Machine Translation (NMT) models mainly focus on the conversion of sequential data and do not directly use syntactic information. However, we conduct multi-source neural machine translation (NMT) models using the multilingual corpora such as string data corpus, tree data corpus, or POS-tagged data corpus. The multi-source translation is an approach to exploit multiple inputs (e.g. in two different formats) to increase translation accuracy. The RNN-based encoder-decoder model with attention mechanism and transformer architectures have been carried out for our experiment. The experimental results showed that the proposed models of RNN-based architecture outperform the baseline model for the English-to-Myanmar translation task, and the multi-source and sharedmulti-source transformer models yield better translation results than the baseline. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Myanmar POS Resource Extension Effects on Automatic Tagging Methods(2020-11-18) ;Hlaing, Zar Zar ;Thu, Ye Kyaw ;Wai, Myat Myo Nwe ;Supnithi, ThepchaiNetisopakul, PonrudeePart-of-speech (POS) tagging is the process of assigning the part-of-speech tag or other lexical class marker to each word in a sentence. It is also one of the most important steps in Natural Language Processing (NLP) task pipeline. There are several research works in Myanmar POS tagging implemented with different approaches. However, there is only one publicly available tagged corpus named myPOS corpus. The size of this corpus is only 11 thousand sentences. It is not enough to train downstream NLP tasks, such as machine learning. For this reason, we manually extended the original myPOS corpus as myPOS version 2.0 and the size of the extended corpus becomes approximately triple size of the original myPOS corpus. To evaluate the effects of the extended corpus versus the original corpus, the accuracies of four supervised tagging algorithms, namely, Conditional Random Fields (CRFs), Hidden Markov Model (HMM), Ripple Down Rules based (RDR), and neural sequence labeling approach of Conditional Random Fields (NCRF++) are compared. The results showed that the extended myPOS version 2.0 improved the accuracies of automatic POS tagging methods compared with the original myPOS. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Increasing SMT and NMT Performance by Corpus Extension with Free Online Machine Translation Services(2020-11-04) ;Hlaing, Zar Zar ;Thu, Ye Kyaw ;Supnithi, ThepchaiNetisopakul, PonrudeeIn machine translation, parallel corpora of source-Target language pair are essential to improve the performance of the translation. However, the existing parallel corpora for the low resource language is not sufficient to improve the quality of the translation. In this paper, we explore the role of corpus extension by using the three freely available online machine translation services; 'Google Translate', 'SYSTRAN Translate' and 'Yandex Translate' for English and Thai language pair. We compare three statistical and neural machine translation performances between the original ASEAN-MT corpus, and their extended version, which double the original size of the ASEAN-MT. The results showed that, for SMT models, extended Thai corpus can help improve the translation performance for th-en translation up to 2.6% and the extended English corpus can do so significantly for en-Th translation up to 4.2%. While for the NMT model, the extended Thai corpus can improve the translation performance up to 5.5%.
