Diyang Chen
2026
PingAn-NLP at SemEval-2026 Task 9: Multi-Stage Alignment via GRPO and Tiered Ensemble Voting for Multilingual Polarization Detection
Diyang Chen | Youzhen Pang
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Diyang Chen | Youzhen Pang
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
This submission describes the PingAn-NLP system for SemEval-2026 Task 9 Subtask 3, identifying polarization manifestations in 18 languages. We employ a tiered optimization framework integrating Supervised Fine-Tuning (SFT) with Group Relative Policy Optimization (GRPO). Key technical innovations include synthetic reasoning distillation from a 235B teacher model , a Smart-Tradeoff reward function designed to mitigate extreme label imbalance , and a tiered ensemble voting strategy that adaptively adjusts decision thresholds based on language resources. Our 8B-GRPO-Vote system demonstrated robust internal performance in tracks like English and Hindi and officially secured second place in the Bengali, English, Odia, and Turkish competitions.
2025
pingan-team at SemEval-2025 Task 2: LoRA-Augmented Qwen2.5 with Wikidata-Driven Entity Translation
Diyang Chen
Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025)
Diyang Chen
Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025)
This paper presents our solution for SemEval-2025 Task 2 on entity-aware machine translation. We propose a parameter-efficient adaptation framework using Low-Rank Adaptation (LoRA) to fine-tune the Qwen2.5-72B model, enabling effective knowledge transfer while preserving generalization capabilities. To address data scarcity and entity ambiguity, we design a Wiki-driven augmentation pipeline that leverages Wikidata’s multilingual entity mappings to generate synthetic training pairs. Our system achieves state-of-the-art performance across 10 languages, securing first place in the competition. Experimental results demonstrate significant improvements in both translation quality (COMET) and entity accuracy (M-ETA).