Yang Cao


2025

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CODEMENV: Benchmarking Large Language Models on Code Migration
Keyuan Cheng | Xudong Shen | Yihao Yang | TengyueWang TengyueWang | Yang Cao | Muhammad Asif Ali | Hanbin Wang | Lijie Hu | Di Wang
Findings of the Association for Computational Linguistics: ACL 2025

Large language models (LLMs) have demonstrated remarkable proficiency in handling a wide range of tasks within the software engineering domain, but their ability to perform code migration—adapting code to different environments—remains underexplored. In this work, we propose a novel benchmark, : Code Migration Across Environment, designed to evaluate LLMs’ performance in handling code migration tasks. The benchmark comprises 922 data points across 19 Python and Java packages, offering three tasks to systematically evaluate code migration: identifying version-incompatible functions, determining function changes, and adapting code to target environments. Experimental evaluation of across seven LLMs revealed an average pass@1 rate of 26.50%, with GPT-4o performing best at 43.84%. We highlight our key findings as follows: (i) LLMs are more familiar with newer function versions, making them better at migrating legacy code, and (ii) a logical inconsistency where LLMs sometimes identify irrelevant function changes for the target migration environment.

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Curr-ReFT: Overcoming Training Bottlenecks in Small-scale Vision-Language Models via Curriculum Reinforcement Finetuning
Huilin Deng | Ding Zou | Xinghao Zhao | Rui Ma | Yanming Guo | Yang Cao | Yu Kang
Findings of the Association for Computational Linguistics: EMNLP 2025

State-of-the-art vision-language models (VLMs) require massive scaling that limits practical deployment. Small-scale VLMs offer a practical alternative but face out-of-domain (OOD) collapse when trained with traditional supervised fine-tuning (SFT). Through GeneralPoints experiments, we identify that OOD collapse is due to SFT’s tendency to induce visual hallucinations under distribution shifts, whereas Reinforcement Learning’s (RL) bidirectional reward-driven mechanism with iterative error correction refines visual perception. Although RL-based post-training effectively mitigates OOD degradation, it faces a critical sparse reward dilemma in complex visual reasoning tasks. To this end, we propose Curriculum Reinforcement Finetuning (Curr-ReFT), comprising two sequential stages: (1) Structured Curriculum Reinforcement Learning, which progressively evolves task formats and reward functions to match models’ growing capabilities; and (2) Rejected Sampling-based Self-improvement, which maintains the fundamental capabilities of VLMs through selective learning from high-quality examples. Extensive experiments demonstrate that Curr-ReFT achieves state-of-the-art performance across various visual tasks in both in- and out-of-domain settings and benchmarks.

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Text Anomaly Detection with Simplified Isolation Kernel
Yang Cao | Sikun Yang | Yujiu Yang | Lianyong Qi | Ming Liu
Findings of the Association for Computational Linguistics: EMNLP 2025

Two-step approaches combining pre-trained large language model embeddings and anomaly detectors demonstrate strong performance in text anomaly detection by leveraging rich semantic representations. However, high-dimensional dense embeddings extracted by large language models pose challenges due to substantial memory requirements and high computation time. To address this challenge, we introduce the Simplified Isolation Kernel (SIK), which maps high-dimensional dense embeddings to lower-dimensional sparse representations while preserving crucial anomaly characteristics. SIK has linear-time complexity and significantly reduces space complexity through its innovative boundary-focused feature mapping.Experiments across 7 datasets demonstrate that SIK achieves better detection performance than 11 SOTA anomaly detection algorithms while maintaining computational efficiency and low memory cost. All code and demonstrations are available at https://github.com/charles-cao/SIK.