Xu Zhong


2025

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Taming the Real-world Complexities in CPT E/M Coding with Large Language Models
Islam Nassar | Yang Lin | Yuan Jin | Rongxin Zhu | Chang Wei Tan | Zenan Zhai | Nitika Mathur | Thanh Tien Vu | Xu Zhong | Long Duong | Yuan-Fang Li
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing: Industry Track

Evaluation and Management (E/M) coding, under the Current Procedural Terminology (CPT) taxonomy, documents medical services provided to patients by physicians. Used primarily for billing purposes, it is in physicians’ best interest to provide accurate CPT E/M codes. Automating this coding task will help alleviate physicians’ documentation burden, improve billing efficiency, and ultimately enable better patient care. However, a number of real-world complexities have made E/M encoding automation a challenging task. In this paper, we elaborate some of the key complexities and present ProFees, our LLM-based framework that tackles them, followed by a systematic evaluation. On an expert-curated real-world dataset, ProFees achieves an increase in coding accuracy of more than 36% over a commercial CPT E/M coding system and almost 5% over our strongest single-prompt baseline, demonstrating its effectiveness in addressing the real-world complexities.

2021

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Grey-box Adversarial Attack And Defence For Sentiment Classification
Ying Xu | Xu Zhong | Antonio Jimeno Yepes | Jey Han Lau
Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

We introduce a grey-box adversarial attack and defence framework for sentiment classification. We address the issues of differentiability, label preservation and input reconstruction for adversarial attack and defence in one unified framework. Our results show that once trained, the attacking model is capable of generating high-quality adversarial examples substantially faster (one order of magnitude less in time) than state-of-the-art attacking methods. These examples also preserve the original sentiment according to human evaluation. Additionally, our framework produces an improved classifier that is robust in defending against multiple adversarial attacking methods. Code is available at: https://github.com/ibm-aur-nlp/adv-def-text-dist.

2020

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Global Locality in Biomedical Relation and Event Extraction
Elaheh ShafieiBavani | Antonio Jimeno Yepes | Xu Zhong | David Martinez Iraola
Proceedings of the 19th SIGBioMed Workshop on Biomedical Language Processing

Due to the exponential growth of biomedical literature, event and relation extraction are important tasks in biomedical text mining. Most work only focus on relation extraction, and detect a single entity pair mention on a short span of text, which is not ideal due to long sentences that appear in biomedical contexts. We propose an approach to both relation and event extraction, for simultaneously predicting relationships between all mention pairs in a text. We also perform an empirical study to discuss different network setups for this purpose. The best performing model includes a set of multi-head attentions and convolutions, an adaptation of the transformer architecture, which offers self-attention the ability to strengthen dependencies among related elements, and models the interaction between features extracted by multiple attention heads. Experiment results demonstrate that our approach outperforms the state of the art on a set of benchmark biomedical corpora including BioNLP 2009, 2011, 2013 and BioCreative 2017 shared tasks.