Zhixing Xu


2024

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Overview of EvaHan2024: The First International Evaluation on Ancient Chinese Sentence Segmentation and Punctuation
Bin Li | Bolin Chang | Zhixing Xu | Minxuan Feng | Chao Xu | Weiguang Qu | Si Shen | Dongbo Wang
Proceedings of the Third Workshop on Language Technologies for Historical and Ancient Languages (LT4HALA) @ LREC-COLING-2024

Ancient Chinese texts have no sentence boundaries and punctuation. Adding modern Chinese punctuation to theses texts requires expertise, time and efforts. Automatic sentence segmentation and punctuation is considered as a basic task for Ancient Chinese processing, but there is no shared task to evaluate the performances of different systems. This paper presents the results of the first ancient Chinese sentence segmentation and punctuation bakeoff, which is held at the Third Workshop on Language Technologies for Historical and Ancient Languages (LT4HALA) 2024. The contest uses metrics for detailed evaluations of 4 genres of unpublished texts with 11 punctuation types. Six teams submitted 32 running results. In the closed modality, the participants are only allowed to use the training data, the highest obtained F1 scores are respectively 88.47% and 75.29% in sentence segmentation and sentence punctuation. The perfermances on the unseen data is 10 percent lower than the published common data, which means there is still space for further improvement. The large language models outperform the traditional models, but LLM changes the original characters around 1-2%, due to over-generation. Thus, post-processing is needed to keep the text consistancy.

2023

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Overview of CCL23-Eval Task 2: The Third Chinese Abstract Meaning Representation Parsing Evaluation
Zhixing Xu | Yixuan Zhang | Bin Li | Zhou Junsheng | Weiguang Qu
Proceedings of the 22nd Chinese National Conference on Computational Linguistics (Volume 3: Evaluations)

“Abstract Meaning Representation has emerged as a prominent area of research in sentence-levelsemantic parsing within the field of natural language processing in recent years. Substantialprogress has been made in various NLP subtasks through the application of AMR. This paperpresents the third Chinese Abstract Meaning Representation Parsing Evaluation, held as part ofthe Technical Evaluation Task Workshop at the 22nd Chinese Computational Linguistics Confer-ence. The evaluation was specifically tailored for the Chinese and utilized the Align-smatch met-ric as the standard evaluation criterion. Building upon high-quality semantic annotation schemesand annotated corpora, this evaluation introduced a new test set comprising interrogative sen-tences for comprehensive evaluation. The results of the evaluation, as measured by the F-score,indicate notable performance achievements. The top-performing team attained a score of 0.8137in the closed test and 0.8261 in the open test, respectively, using the Align-smatch metric. No-tably, the leading result surpassed the SOTA performance at CoNLL 2020 by 3.64 percentagepoints when evaluated using the MRP metric. Further analysis revealed that this significantprogress primarily stemmed from improved relation prediction between concepts. However, thechallenge of effectively utilizing semantic relation alignments remains an area that requires fur-ther enhancement.”

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A Joint Model of Automatic Word Segmentation and Part-Of-Speech Tagging for Ancient Classical Texts Based on Radicals
Bolin Chang | Yiguo Yuan | Bin Li | Zhixing Xu | Minxuan Feng | Dongbo Wang
Proceedings of the Ancient Language Processing Workshop

The digitization of ancient books necessitates the implementation of automatic word segmentation and part-of-speech tagging. However, the existing research on this topic encounters pressing issues, including suboptimal efficiency and precision, which require immediate resolution. This study employs a methodology that combines word segmentation and part-of-speech tagging. It establishes a correlation between fonts and radicals, trains the Radical2Vec radical vector representation model, and integrates it with the SikuRoBERTa word vector representation model. Finally, it connects the BiLSTM-CRF neural network.The study investigates the combination of word segmentation and part-of-speech tagging through an experimental approach using a specific data set. In the evaluation dataset, the F1 score for word segmentation is 95.75%, indicating a high level of accuracy. Similarly, the F1 score for part-of-speech tagging is 91.65%, suggesting a satisfactory performance in this task. This model enhances the efficiency and precision of the processing of ancient books, thereby facilitating the advancement of digitization efforts for ancient books and ensuring the preservation and advancement of ancient book heritage.

2022

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Align-smatch: A Novel Evaluation Method for Chinese Abstract Meaning Representation Parsing based on Alignment of Concept and Relation
Liming Xiao | Bin Li | Zhixing Xu | Kairui Huo | Minxuan Feng | Junsheng Zhou | Weiguang Qu
Proceedings of the Thirteenth Language Resources and Evaluation Conference

Abstract Meaning Representation is a sentence-level meaning representation, which abstracts the meaning of sentences into a rooted acyclic directed graph. With the continuous expansion of Chinese AMR corpus, more and more scholars have developed parsing systems to automatically parse sentences into Chinese AMR. However, the current parsers can’t deal with concept alignment and relation alignment, let alone the evaluation methods for AMR parsing. Therefore, to make up for the vacancy of Chinese AMR parsing evaluation methods, based on AMR evaluation metric smatch, we have improved the algorithm of generating triples so that to make it compatible with concept alignment and relation alignment. Finally, we obtain a new integrity metric align-smatch for paring evaluation. A comparative research then was conducted on 20 manually annotated AMR and gold AMR, with the result that align-smatch works well in alignments and more robust in evaluating arcs. We also put forward some fine-grained metric for evaluating concept alignment, relation alignment and implicit concepts, in order to further measure parsers’ performance in subtasks.