Large Language Models (LLMs) have enabled remarkable progress in natural language processing, yet their high computational and memory demands pose challenges for deployment in resource-constrained environments. Although recent low-rank decomposition methods offer a promising path for structural compression, they often suffer from accuracy degradation, expensive calibration procedures, and result in inefficient model architectures that hinder real-world inference speedups. In this paper, we propose FLAT-LLM, a fast and accurate, training-free structural compression method based on fine-grained low-rank transformations in the activation space. Specifically, we reduce the hidden dimension by transforming the weights using truncated eigenvectors computed via head-wise Principal Component Analysis, and employ a greedy budget redistribution strategy to adaptively allocate ranks across decoders. FLAT-LLM achieves efficient and effective weight compression without recovery fine-tuning, which could complete the calibration within a few minutes.Evaluated across 5 models and 11 datasets, FLAT-LLM outperforms structural pruning baselines in generalization and downstream performance, while delivering inference speedups over decomposition-based methods.

Document-grounded dialogue generation based on multilingual is a challenging and realistic task. Unlike previous tasks, it need to tackle with multiple high-resource languages facilitating low-resource languages. This paper summarizes our research based on a three-stage pipeline that includes retrieval, re-rank and generation where each component is individually optimized. In different languages with limited data scenarios, we mainly improve the robustness of the pipeline through data augmentation and embedding perturbation with purpose of improving the performance designing three training methods: cross-language enhancement training, weighted training with neighborhood distribution augmentation, and ensemble adversarial training, all of that can be used as plug and play modules. Through experiments with different settings, it has been shown that our methods can effectively improve the generalization performance of pipeline with score ranking 6th among the public submissions on leaderboards.