Yuxi Chen


2024

pdf bib
Transformers Learn Transition Dynamics when Trained to Predict Markov Decision Processes
Yuxi Chen | Suwei Ma | Tony Dear | Xu Chen
Proceedings of the 7th BlackboxNLP Workshop: Analyzing and Interpreting Neural Networks for NLP

Language models have displayed a wide array of capabilities, but the reason for their performance remains a topic of heated debate and investigation. Do these models simply recite the observed training data, or are they able to abstract away surface statistics and learn the underlying processes from which the data was generated? To investigate this question, we explore the capabilities of a GPT model in the context of Markov Decision Processes (MDPs), where the underlying transition dynamics and policies are not directly observed. The model is trained to predict the next state or action without any initial knowledge of the MDPs or the players’ policies. Despite this, we present evidence that the model develops emergent representations of the underlying parameters governing the MDPs.

2023

pdf bib
Sea_and_Wine at SemEval-2023 Task 9: A Regression Model with Data Augmentation for Multilingual Intimacy Analysis
Yuxi Chen | Yu Chang | Yanqing Tao | Yanru Zhang
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

In Task 9, we are required to analyze the textual intimacy of tweets in 10 languages. We fine-tune XLM-RoBERTa (XLM-R) pre-trained model to adapt to this multilingual regression task. After tentative experiments, severe class imbalance is observed in the official released dataset, which may compromise the convergence and weaken the model effect. To tackle such challenge, we take measures in two aspects. On the one hand, we implement data augmentation through machine translation to enlarge the scale of classes with fewer samples. On the other hand, we introduce focal mean square error (MSE) loss to emphasize the contributions of hard samples to total loss, thus further mitigating the impact of class imbalance on model effect. Extensive experiments demonstrate remarkable effectiveness of our strategies, and our model achieves high performance on the Pearson’s correlation coefficient (CC) almost above 0.85 on validation dataset.

pdf bib
niceNLP at SemEval-2023 Task 10: Dual Model Alternate Pseudo-labeling Improves Your Predictions
Yu Chang | Yuxi Chen | Yanru Zhang
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

Sexism is a growing online problem. It harms women who are targeted and makes online spaces inaccessible and unwelcoming. In this paper, we present our approach for Task A of SemEval-2023 Task 10: Explainable Detection of Online Sexism (EDOS), which aims to perform binary sexism detection on textual content. To solve this task, we fine-tune the pre-trained model based on several popular natural language processing methods to improve the generalization ability in the face of different data. According to the experimental results, the effective combination of multiple methods enables our approach to achieve excellent performance gains.

2022

pdf bib
zydhjh4593@SMM4H’22: A Generic Pre-trained BERT-based Framework for Social Media Health Text Classification
Chenghao Huang | Xiaolu Chen | Yuxi Chen | Yutong Wu | Weimin Yuan | Yan Wang | Yanru Zhang
Proceedings of The Seventh Workshop on Social Media Mining for Health Applications, Workshop & Shared Task

This paper describes our proposed framework for the 10 text classification tasks of Task 1a, 2a, 2b, 3a, 4, 5, 6, 7, 8, and 9, in the Social Media Mining for Health (SMM4H) 2022. According to the pre-trained BERT-based models, various techniques, including regularized dropout, focal loss, exponential moving average, 5-fold cross-validation, ensemble prediction, and pseudo-labeling, are applied for further formulating and improving the generalization performance of our framework. In the evaluation, the proposed framework achieves the 1st place in Task 3a with a 7% higher F1-score than the median, and obtains a 4% higher averaged F1-score than the median in all participating tasks except Task 1a.