Cheng Deng
2026
Rotation Control Unlearning: Quantifying and Controlling Continuous Unlearning for LLM with The Cognitive Rotation Space
Xiang Zhang | Kun Wei | Xu Yang | Jiahua Li | Su Yan | Cheng Deng
Findings of the Association for Computational Linguistics: ACL 2026
Xiang Zhang | Kun Wei | Xu Yang | Jiahua Li | Su Yan | Cheng Deng
Findings of the Association for Computational Linguistics: ACL 2026
As Large Language Models (LLMs) become increasingly prevalent, their security vulnerabilities have already drawn attention.Machine unlearning is introduced to seek to mitigate these risks by removing the influence of undesirable data. However, existing methods not only rely on the retained dataset to preserve model utility, but also suffer from cumulative catastrophic utility loss under continuous unlearning requests.To solve this dilemma, we propose a novel method, called Rotation Control Unlearning (RCU), which leverages the rotational salience weight of RCU to quantify and control the unlearning degree in the continuous unlearning process.The skew symmetric loss is designed to construct the existence of the cognitive rotation space, where the changes of rotational angle can simulate the continuous unlearning process.Furthermore, we design an orthogonal rotation axes regularization to enforce mutually perpendicular rotation directions for continuous unlearning requests, effectively minimizing interference and addressing cumulative catastrophic utility loss.Experiments on multiple datasets confirm that our continuous unlearning method without retained dataset achieves SOTA performance.
GR1: Reinforcement-Enhanced LLM for Geoscience Reasoning
Yule Xie | Jiaxin Ding | Cheng Deng | Shiqing Gao | Junran Zhang | Sibo Zhang | Zeyuan Wang | Ke Wu | Xin Ding | Luoyi Fu | Meng Jin | Xinbing Wang
Findings of the Association for Computational Linguistics: ACL 2026
Yule Xie | Jiaxin Ding | Cheng Deng | Shiqing Gao | Junran Zhang | Sibo Zhang | Zeyuan Wang | Ke Wu | Xin Ding | Luoyi Fu | Meng Jin | Xinbing Wang
Findings of the Association for Computational Linguistics: ACL 2026
Reinforcement learning (RL) has recently shown remarkable ability to enhance reasoning in large language models (LLMs), yet its potential in scientific domains beyond mathematics remains largely unexplored. Geoscience questions couple broad factual knowledge with multi-step inference and often rely on visual evidence such as maps, cross-sections, and diagrams, making them a challenging but verifiable testbed for RL-based reasoning. To enable this study, we introduce GeoMC-10K, a dataset of 10,000 geoscience multiple-choice questions spanning physical to human geography and high-school to professional levels; over 30% of the questions are image dependent. To support text-only RL on these multimodal questions, we design GeoM2T, a multi-agent framework that converts multimodal questions into descriptive text while preserving answerability and difficulty. Fine-tuning LLaMA-3.1-8B and Qwen-3-8B with Group Relative Policy Optimization (GRPO), incorporating a factual reward mechanism, yields GR1, which achieves absolute accuracy improvements of 5.9% and 13.3%, respectively, and it generalizes to out-of-distribution geoscience benchmarks. Together, GeoMC-10K, GeoM2T, and GR1 establish a scalable benchmark and baseline for RL-enhanced geoscience reasoning.
Logical Structure as Knowledge: Enhancing LLM Reasoning via Structured Logical Knowledge Density Estimation
Zhen Bi | Zhenlin Hu | Xueshu Chen | Mingyang Chen | Cheng Deng | Yida Xue | Zhen Wang | Qing Shen | Ningyu Zhang | Jungang Lou
Findings of the Association for Computational Linguistics: ACL 2026
Zhen Bi | Zhenlin Hu | Xueshu Chen | Mingyang Chen | Cheng Deng | Yida Xue | Zhen Wang | Qing Shen | Ningyu Zhang | Jungang Lou
Findings of the Association for Computational Linguistics: ACL 2026
The reasoning capabilities of Large Language Models (LLMs) are increasingly attributed to training data quality rather than mere parameter scaling. However, existing data-centric paradigms often equate quality with factuality or diversity and ignore the internal logical complexity of training samples. In this work, we propose that natural language harbors Structured Logical Knowledge manifested through entailment relationships and logical topologies. To quantify this, we introduce Structured Logical Knowledge Density (SLKD), a novel metric that measures logical information content by decomposing natural language into executable predicates and logical primitives. Our analysis reveals a significant logical disparity in current datasets where sparse logical signals predominate. Consequently, we propose a density-aware re-cognizing optimization strategy that prioritizes high-density logical samples to align training with the model’s reasoning boundary. Extensive experiments demonstrate that our approach enhances reasoning performance and generalization without increasing total data volume. These results, further validated within a reinforcement learning framework, suggest that elevating logical density is more critical than expanding data scale for realizing the full cognitive potential of LLMs. The anonymized code is available in the Appendix C.
Semantically Comprehensive Token Pruning in LVLMs via Maximizing Concept Coverage
Xueting Li | Qi Liu | Chenghao Xu | Xu Yang | Guangtao Lyu | Jiahua Li | Cheng Deng
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Xueting Li | Qi Liu | Chenghao Xu | Xu Yang | Guangtao Lyu | Jiahua Li | Cheng Deng
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
High-resolution visual tokens impose substantial computational burdens owing to extreme redundancy in Large Visual Language Models (LVLMs). Existing visual token pruning methods typically leverage simple metrics derived from human experience, such as attention or similarity, to rank and select tokens within a highly entangled feature space. However, these metrics lack interpretability and often introduce human bias, failing to capture the genuine semantic significance of tokens, especially amidst the inherent semantic complexity and ambiguity of visual tokens. To mitigate this limitation, we propose a novel Semantically Comprehensive Token Selection (SCTS) method for unbiased, interpretable visual token pruning via a concept-driven paradigm. To unravel the model’s intrinsic semantic representation mechanism, we first introduce a Sparse Autoencoder to disentangle visual features into an interpretable space, with each dimension encoding a distinct semantic concept. We then formulate the token pruning task as a Maximum Concept Coverage problem, quantifying the Marginal Semantic Gain (MSG) of each token’s contribution to uncovered concepts and iteratively selecting tokens with the highest MSG. This concept-centric approach prioritizes tokens with unique semantic contributions, guaranteeing semantic comprehensiveness while preserving robust performance even at high compression ratios. Extensive experiments across multiple LVLM architectures and benchmarks verify that SCTS consistently outperforms state-of-the-art approaches, achieving a superior trade-off between computational efficiency and semantic completeness.
Revealing and Enhancing Core Visual Regions: Harnessing Internal Attention Dynamics for Hallucination Mitigation in LVLMs
Guangtao Lyu | Qi Liu | Chenghao Xu | Jiexi Yan | Muli Yang | Xueting Li | Fen Fang | Cheng Deng
Findings of the Association for Computational Linguistics: ACL 2026
Guangtao Lyu | Qi Liu | Chenghao Xu | Jiexi Yan | Muli Yang | Xueting Li | Fen Fang | Cheng Deng
Findings of the Association for Computational Linguistics: ACL 2026
LVLMs have achieved strong multimodal reasoning capabilities but remain prone to hallucinations, producing outputs inconsistent with visual inputs or user instructions. Existing training-free methods, including contrastive decoding and auxiliary expert models, which incur several times more computational overhead and may introduce potential interference, as well as static internal signal enhancement, are often vulnerable to the attention sink phenomenon. We find that internal Positive Attention Dynamics (PAD) in LVLMs naturally reveal semantically core visual regions under the distortions of attention sinks. Based on this, we propose Positive Attention Dynamics Enhancement (PADE), a training-free attention intervention that constructs a PAD map to identify semantically core visual regions, applies per-head Median Absolute Deviation Scaling to adaptively control the intervention strength, and leverages System-Token Compensation to maintain attention to complex user instructions and support long-term output consistency. Experiments on multiple LVLMs and benchmarks show that PADE improves visual grounding and reduces hallucinations, validating the effectiveness of leveraging internal attention dynamics for reliable multimodal reasoning.
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.
VisPCO: Visual Token Pruning Configuration Optimization via Budget-Aware Pareto-Frontier Learning for Vision-Language Models
Huawei Ji | Yuanhao Sun | Yuan Jin | Cheng Deng | Jiaxin Ding | Luoyi Fu | Xinbing Wang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Huawei Ji | Yuanhao Sun | Yuan Jin | Cheng Deng | Jiaxin Ding | Luoyi Fu | Xinbing Wang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Visual token pruning methods effectively mitigate the quadratic computational growth caused by processing high-resolution images and video frames in vision-language models (VLMs). However, existing approaches rely on predefined pruning configurations without determining whether they achieve computation-performance optimality. In this work, we introduce , a novel framework that formulates visual token pruning as a Pareto configuration optimization problem to automatically identify optimal configurations. Our approach employs continuous relaxation and straight-through estimators to enable gradient-based search, solved via the Augmented Lagrangian method. Extensive experiments across 8 visual benchmarks demonstrate that effectively approximates the empirical Pareto frontier obtained through grid search and generalizes well across various pruning methods and VLM architectures. Furthermore, through learnable kernel functions, we investigate layer-wise pruning patterns and reveal that multi-step progressive pruning captures VLMs’ hierarchical compression structure, achieving superior accuracy-efficiency trade-offs compared to single-layer approaches.
Fisher-Driven Adaptive Locating for Knowledge Editing in Large Language Models
Chenghao Xu | Jiexi Yan | Guangtao Lyu | Qi Liu | Muli Yang | Cheng Deng
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Chenghao Xu | Jiexi Yan | Guangtao Lyu | Qi Liu | Muli Yang | Cheng Deng
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Large language models (LLMs) store extensive factual knowledge acquired during pretraining, yet this knowledge is inherently static and may become inaccurate or outdated, leading to knowledge hallucinations. Knowledge editing offers an efficient alternative to full retraining by enabling targeted factual updates while preserving overall model behavior. Existing locate-then-edit methods, however, rely on fixed layer selection strategies, treating the locating stage as a static design choice and failing to account for the hierarchical and instance-dependent nature of knowledge representation in LLMs. In this paper, we propose FiDAL, a Fisher-driven adaptation-aware locating strategy that dynamically identifies which model components should be edited for a given knowledge update. FiDAL formulates localization as a weight-level decision problem and leverages Fisher Information to select layers that are both influential and sensitive to factual modifications. A lightweight probing stage with low-rank modulation enables efficient localization with minimal overhead. Experiments on standard benchmarks demonstrate that FiDAL consistently improves editing effectiveness and knowledge preservation across multiple editing methods.
2024
Exploiting Intrinsic Multilateral Logical Rules for Weakly Supervised Natural Language Video Localization
Zhe Xu | Kun Wei | Xu Yang | Cheng Deng
Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Zhe Xu | Kun Wei | Xu Yang | Cheng Deng
Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Weakly supervised natural language video localization (WS-NLVL) aims to retrieve the moment corresponding to a language query in a video with only video-language pairs utilized during training. Despite great success, existing WS-NLVL methods seldomly consider the complex temporal relations enclosing the language query (e.g., between the language query and sub-queries decomposed from it or its synonymous query), yielding illogical predictions. In this paper, we propose a novel plug-and-play method, Intrinsic Multilateral Logical Rules, namely IMLR, to exploit intrinsic temporal relations and logical rules for WS-NLVL. Specifically, we formalize queries derived from the original language query as the nodes of a directed graph, i.e., intrinsic temporal relation graph (ITRG), and the temporal relations between them as the edges. Instead of directly prompting a pre-trained language model, a relation-guided prompting method is introduced to generate ITRG in a hierarchical manner. We customize four types of multilateral temporal logical rules (i.e., identity, inclusion, synchronization, and succession) from ITRG and utilize them to train our model. Experiments demonstrate the effectiveness and superiority of our method on the Charades-STA and ActivityNet Captions datasets.
LLM Knows Body Language, Too: Translating Speech Voices into Human Gestures
Chenghao Xu | Guangtao Lyu | Jiexi Yan | Muli Yang | Cheng Deng
Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Chenghao Xu | Guangtao Lyu | Jiexi Yan | Muli Yang | Cheng Deng
Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
In response to the escalating demand for digital human representations, progress has been made in the generation of realistic human gestures from given speeches. Despite the remarkable achievements of recent research, the generation process frequently includes unintended, meaningless, or non-realistic gestures. To address this challenge, we propose a gesture translation paradigm, GesTran, which leverages large language models (LLMs) to deepen the understanding of the connection between speech and gesture and sequentially generates human gestures by interpreting gestures as a unique form of body language. The primary stage of the proposed framework employs a transformer-based auto-encoder network to encode human gestures into discrete symbols. Following this, the subsequent stage utilizes a pre-trained LLM to decipher the relationship between speech and gesture, translating the speech into gesture by interpreting the gesture as unique language tokens within the LLM. Our method has demonstrated state-of-the-art performance improvement through extensive and impartial experiments conducted on public TED and TED-Expressive datasets.
2023
Enhancing Uncertainty-Based Hallucination Detection with Stronger Focus
Tianhang Zhang | Lin Qiu | Qipeng Guo | Cheng Deng | Yue Zhang | Zheng Zhang | Chenghu Zhou | Xinbing Wang | Luoyi Fu
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Tianhang Zhang | Lin Qiu | Qipeng Guo | Cheng Deng | Yue Zhang | Zheng Zhang | Chenghu Zhou | Xinbing Wang | Luoyi Fu
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Large Language Models (LLMs) have gained significant popularity for their impressive performance across diverse fields. However, LLMs are prone to hallucinate untruthful or nonsensical outputs that fail to meet user expectations in many real-world applications. Existing works for detecting hallucinations in LLMs either rely on external knowledge for reference retrieval or require sampling multiple responses from the LLM for consistency verification, making these methods costly and inefficient. In this paper, we propose a novel reference-free, uncertainty-based method for detecting hallucinations in LLMs. Our approach imitates human focus in factuality checking from three aspects: 1) focus on the most informative and important keywords in the given text; 2) focus on the unreliable tokens in historical context which may lead to a cascade of hallucinations; and 3) focus on the token properties such as token type and token frequency. Experimental results on relevant datasets demonstrate the effectiveness of our proposed method, which achieves state-of-the-art performance across all the evaluation metrics and eliminates the need for additional information.
Search
Fix author
Co-authors
- Guangtao Lyu 4
- Chenghao Xu 4
- Luoyi Fu 3
- Qi Liu 3
- Xinbing Wang 3
- Jiexi Yan 3
- Xu Yang 3
- Muli Yang 3
- Jiaxin Ding 2
- Jiahua Li 2
- Xueting Li 2
- Kun Wei 2
- Zhen Bi 1
- Xueshu Chen 1
- Mingyang Chen 1
- Xin Ding 1
- Fen Fang 1
- Shiqing Gao 1
- Qipeng Guo 1
- Zhenlin Hu 1
- Huawei Ji 1
- Meng Jin 1
- Yuan Jin 1
- Guangyan Li 1
- Jungang Lou 1
- Lin Qiu 1
- Qing Shen 1
- Luoyang Sun 1
- Yuanhao Sun 1
- Yongqiang Tang 1
- Zeyuan Wang 1
- Zhen Wang 1
- Jun Wang 1
- Ke Wu 1
- Yule Xie 1
- Zhe Xu 1
- Yida Xue 1
- Su Yan 1
- Xiang Zhang 1
- Junran Zhang 1
- Sibo Zhang 1
- Ningyu Zhang 1
- Tianhang Zhang 1
- Yue Zhang 1
- Zheng Zhang 1
- Haifeng Zhang 1
- Wensheng Zhang 1
- Jian Zhao 1
- Chenghu Zhou 1