nnvlp - A Neural Network-Based Vietnamese Language Processing Toolkit

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Code by Thai-Hoang Pham at Alt Inc. (Utilize some code at a repository)

A demo website is available at nnvlp.org

1. Introduction

nnvlp is a Python package of the system described in a paper NNVLP: A Neural Network-Based Vietnamese Language Processing Toolkit. This package is used for some common sequence labeling tasks for Vietnamese including part-of-speech (POS) tagging, chunking, named entity recognition (NER). The architecture of a model in this package is the combination of bi-directional Long Short-Term Memory (Bi-LSTM), Conditional Random Field (CRF), and word embeddings that is the concatenation of pre-trained word embeddings learnt from skip-gram model and character-level word features learnt from Convolutional Neural Network (CNN).

Our package achieves an accuracy of 91.92%, F1 scores of 84.11% and 92.91% for POS tagging, chunking, and NER tasks respectively.

The following tables compare the performance of nnvlp and other previous toolkit on POS tagging, chunking, and NER task respectively.

POS tagging

System	Accuracy
Vitk	88.41
vTools	90.73
RDRPOSTagger	91.96
nnvlp	91.92

Chunking

System	P	R	F1
vTools	82.79	83.55	83.17
nnvlp	83.93	84.28	84.11

NER

System	P	R	F1
Vitk	88.36	89.20	88.78
vie-ner-lstm	91.09	93.03	92.05
nnvlp	92.76	93.07	92.91

2. Installation

The simple way to install nnvlp is using pip:

    $ pip install nnvlp

3. Usage

    >>> import nnvlp
    >>> model = nnvlp.NNVLP()
    >>> output = model.predict(u"Hôm nay tôi ra Hà Nội gặp ông Nam. Ông Nam là giảng viên đại học Bách Khoa.")

The default output is a dict that contains token_text, pos, chunk, ner attributes. At this version, there are two other display formats including CoNLL and JSON. If you want to get easy-to-read format, you can use CoNLL option.

    >>> import nnvlp
    >>> model = nnvlp.NNVLP()
    >>> output = model.predict(u"Hôm nay tôi ra Hà Nội gặp ông Nam. Ông Nam là giảng viên đại học Bách Khoa.", display_format="CoNLL")
    >>> print output
    1	Hôm_nay		N		B-NP		O
    2	tôi		P		B-NP		O
    3	ra		V		B-VP		O
    4	Hà_Nội		Np		B-NP		B-LOC
    5	gặp		V		B-VP		O
    6	ông		Nc		B-NP		O
    7	Nam		Np		I-NP		B-PER
    8	.		CH		O		O
    
    1	Ông		Nc		B-NP		O
    2	Nam		Np		I-NP		B-PER
    3	là		V		B-VP		O
    4	giảng_viên		N		B-NP		O
    5	đại_học		N		B-NP		B-ORG
    6	Bách_Khoa		Np		I-NP		I-ORG
    7	.		CH		O		O

Note: This version works only for MAC OS and Linux environments. Installing nnvlp package may take a few minutes because it downloads Vietnamese word embeddings and NLTK data from Internet if you don't have them installed before.

4. References

Thai-Hoang Pham, Xuan-Khoai Pham, Tuan-Anh Nguyen, Phuong Le-Hong, "NNVLP: A Neural Network-Based Vietnamese Language Processing Toolkit" Proceedings of The 8th International Joint Conference on Natural Language Processing (IJCNLP 2017)

@inproceedings{Pham:2017b,
  title={NNVLP: A Neural Network-Based Vietnamese Language Processing Toolkit},
  author={Thai-Hoang Pham and Xuan-Khoai Pham and Tuan-Anh Nguyen and Phuong Le-Hong},
  booktitle={Proceedings of The 8th International Joint Conference on Natural Language Processing},
  year={2017},
}

Thai-Hoang Pham, Phuong Le-Hong, "End-to-end Recurrent Neural Network Models for Vietnamese Named Entity Recognition: Word-level vs. Character-level" Proceedings of The 15th International Conference of the Pacific Association for Computational Linguistics (PACLING 2017)

@inproceedings{Pham:2017a,
  title={End-to-end Recurrent Neural Network Models for Vietnamese Named Entity Recognition: Word-level vs. Character-level},
  author={Thai-Hoang Pham and Phuong Le-Hong},
  booktitle={Proceedings of The 15th International Conference of the Pacific Association for Computational Linguistics},
  year={2017},
}

5. Contact

Thai-Hoang Pham < phamthaihoang.hn@gmail.com >

Alt Inc, Hanoi, Vietnam