Haifeng Zhang
Author directory2026
Remember and Reweight: Enhancing Multi-Agent Debate with Experience Memory and Confidence Estimation
Xuanfa Jin | Zhijian Ma | Yongcheng Zeng | Xinyu Cui | Haifeng Zhang | Jun Wang
Findings of the Association for Computational Linguistics: EMNLP 2026
Xuanfa Jin | Zhijian Ma | Yongcheng Zeng | Xinyu Cui | Haifeng Zhang | Jun Wang
Findings of the Association for Computational Linguistics: EMNLP 2026
Multi-agent debate (MAD) improves the reasoning capabilities of large language models by having multiple agents iteratively refine their responses through discussion. However, MAD suffers from a critical vulnerability known as shared misconception: when a majority of agents initially converge on an incorrect answer, the debate process tends to amplify rather than correct the error. Existing methods primarily address peer skew but leave the agents’ inherently biased concept priors unaddressed. To mitigate this systematic weakness, we propose **R2-MAD** (Remember and Reweight for Multi-Agent Debate), a framework that equips agents with an experience memory accumulated from past debates. R2-MAD intervenes on both failure modes through two complementary mechanisms: A debate-state-aware retrieval policy dynamically calibrates the concept prior by retrieving relevant historical evidence based on the current consensus level. Then these retrieved experiences provide a basis for estimating per-agent reliability, yielding confidence weights to modulate peer influence. Experiments on various benchmarks show that R2-MAD achieves consistent improvements over existing single-agent and MAD baselines.
Kurtosis-Aware Coupled Sparsity: Training-Free Activation Sparsity for Large Language Models
Guangyan Li | Luoyang Sun | Siyuan Li | Haifeng Zhang | Yongqiang Tang | Wensheng Zhang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Guangyan Li | Luoyang Sun | Siyuan Li | Haifeng Zhang | Yongqiang Tang | Wensheng Zhang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
The massive scale of Large Language Models (LLMs) incurs prohibitive computational costs, limiting their ubiquitous deployment. While activation sparsity is a promising training-free solution, existing magnitude-based methods overlook weight structures and dependencies. We reveal that standard weight norms fail as importance proxies, identifying instead that weight distribution heavy-tailedness is critical. To this end, we propose Kurtosis-Aware Coupled Sparsity (KACS), a novel training-free framework that introduces a Kurtosis-based metric to explicitly capture and prioritize outlier-rich weight columns. Furthermore, we develop an Interaction-Aware evaluation mechanism that assesses the joint importance of structurally coupled projections (e.g., Gate-Up and Q-K-V), ensuring information retention across interacting pathways. In addition, an adaptive sparsity allocation strategy is employed to distribute the sparsity budget across layers and components. Extensive experiments on Llama and Mistral models demonstrate that KACS consistently outperforms state-of-the-art baselines, retaining over 97% of the original performance at 50% sparsity.
UniMem: Complementary Episodic-to-Parametric Memory for Boundary-Agnostic Task Streams
Siyu Xia | Chenheng Zhang | Yanting Wu | Haoxuan Li | Jiajun Chai | Xiaohan Wang | Guojun Yin | Wei Lin | Zhouchen Lin | Haifeng Zhang | Jun Wang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Siyu Xia | Chenheng Zhang | Yanting Wu | Haoxuan Li | Jiajun Chai | Xiaohan Wang | Guojun Yin | Wei Lin | Zhouchen Lin | Haifeng Zhang | Jun Wang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Memory is essential for LLM agents to accumulate task experience and reuse task-specific execution strategies. However, real-world deployment over boundary-agnostic and evolving task streams exposes a fundamental stability-plasticity dilemma. External retrieval-based memory can rapidly absorb new evidence, but it often fails to internalize recurring execution patterns and incurs inference-time retrieval overhead. Parametric memory enables stable and efficient execution once learned, but typically relies on explicit task boundaries and fixed parameter budgets. Inspired by the human brain, which balances plasticity and stability through complementary episodic storage and gradual consolidation, we propose UniMem, a self-routing framework for autonomous memory management. UniMem uses learnable routing tokens as memory controllers, enabling adaptive coordination between complementary memory pathways: novel or sparse tasks are retained in an episodic buffer for retrieval-augmented execution, while recurring and reliable patterns are consolidated into expandable parametric memory. By decoupling task identification from task execution with routing tokens and parametric memory blocks, UniMem expands memory on demand without task labels during deployment or uncontrolled parameter growth. Experiments on long-horizon streaming task sequences show that UniMem typically achieves strong aggregate results while maintaining routing and execution stability, with an average gain of 4.0 EM over Replay LoRA.
Dual Activation-Weight Sparsity: A Training-Free Framework for Efficient Large Language Model Compression
Luoyang Sun | Guangyan Li | Cheng Deng | Haifeng Zhang | Jian Zhao | Yongqiang Tang | Wensheng Zhang | Jun Wang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Luoyang Sun | Guangyan Li | Cheng Deng | Haifeng Zhang | Jian Zhao | Yongqiang Tang | Wensheng Zhang | Jun Wang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Large language models (LLMs) excel at natural language tasks but face deployment challenges due to computational demands. We introduce Dual Activation-Weight Sparsity (DAWS), a training-free framework that jointly exploits activation and weight sparsity through magnitude-based routing. Systematic analysis of pretrained transformers reveals two key observations: (1) the activation energy is concentrated in a few neurons, and (2) activation and weight sparsity patterns are complementary between attention and FFN layers. DAWS employs a three-tier routing strategy: high-magnitude activations pass through full-precision weights to preserve critical pathways, medium-magnitude activations use magnitude-pruned sparse weights for efficiency, and low-magnitude activations are directly discarded. Unlike prior work that uses activation-aware pruning methods like WANDA, our approach uses direct magnitude-based pruning, which we show is more robust to sample-level variations. Experiments on Llama and Mistral models demonstrate that DAWS maintains >98% of dense model performance at 50% sparsity, outperforming WANDA, TEAL, and R-Sparse.