Jianchao Tan
Author directory2026
MONA: Muon Optimizer with Nesterov Acceleration for Scalable Language Model Training
Jiacheng Li | Jianchao Tan | Hongtao Xu | Jiaqi Zhang | Yifan Lu | Yerui Sun | Yuchen Xie | Xunliang Cai
Findings of the Association for Computational Linguistics: EMNLP 2026
Jiacheng Li | Jianchao Tan | Hongtao Xu | Jiaqi Zhang | Yifan Lu | Yerui Sun | Yuchen Xie | Xunliang Cai
Findings of the Association for Computational Linguistics: EMNLP 2026
The Muon optimizer has recently offered a promising alternative to AdamW for large language model training, leveraging matrix orthogonalization to produce geometry-aware updates. However, like all first-order methods, Muon can become trapped in sharp local minima. In this work, we present **MONA**, an optimizer that bridges Muon’s orthogonalization framework with curvature-aware acceleration. MONA adds an acceleration term directly into Muon’s gradient processing pipeline. This term is calculated from the exponential moving average of gradient differences. We provide a detailed convergence analysis for MONA, showing that the acceleration term enables escape from sharp minima while preserving Muon’s spectral-norm regularization. Empirically, MONA achieves better convergence and downstream task performance compared to both Muon and AdamW across three scales of Mixture-of-Experts pretraining, spanning from 1B to 68B parameters, with the largest model trained on 1 trillion tokens. Furthermore, we conduct supervised fine-tuning on the MOE-68B-A3B model and evaluate it on general capability, mathematical reasoning, and code generation benchmarks, where MONA achieves **SOTA** performance.
Accelerate Speculative Decoding with Sparse Computation in Verification
Jikai Wang | Jianchao Tan | Yuxuan Hu | Jiayu Qin | Yerui Sun | Yuchen Xie | Xunliang Cai | Juntao Li | Min Zhang
Findings of the Association for Computational Linguistics: EMNLP 2026
Jikai Wang | Jianchao Tan | Yuxuan Hu | Jiayu Qin | Yerui Sun | Yuchen Xie | Xunliang Cai | Juntao Li | Min Zhang
Findings of the Association for Computational Linguistics: EMNLP 2026
Speculative decoding accelerates autoregressive language model inference by verifying multiple draft tokens in parallel. However, the verification stage often becomes the dominant computational bottleneck, especially for long-context inputs and mixture-of-experts (MoE) models. Existing sparsification methods are designed primarily for token-by-token autoregressive decoding to remove substantial computational redundancy in LLMs. This work systematically adopts different sparse methods on the verification stage of the speculative decoding and identifies structured redundancy across multiple dimensions. Based on these observations, we propose a sparse verification framework that jointly sparsifies attention, FFN, and MoE components during the verification stage to reduce the dominant computation cost. The framework further incorporates an inter-draft token and inter-layer retrieval reuse strategy to further reduce redundant computation without introducing additional training. Extensive experiments across summarization, question answering, and mathematical reasoning datasets demonstrate that the proposed methods achieve favorable efficiency-accuracy trade-offs and can be translated into practical latency reduction with optimized sparse kernels.
WISCA: A Lightweight Model Transition Method to Improve LLM Training via Weight Scaling
Jiacheng Li | Jianchao Tan | Zhidong Yang | Pingwei Sun | Feiye Huo | Jiayu Qin | Xiangyu Zhang | Maoxin He | Guangming Tan | Weile Jia | Xunliang Cai | Tong Zhao
Findings of the Association for Computational Linguistics: ACL 2026
Jiacheng Li | Jianchao Tan | Zhidong Yang | Pingwei Sun | Feiye Huo | Jiayu Qin | Xiangyu Zhang | Maoxin He | Guangming Tan | Weile Jia | Xunliang Cai | Tong Zhao
Findings of the Association for Computational Linguistics: ACL 2026
Transformer architecture gradually dominates the LLM field. Recent advances in training optimization for Transformer-based large language models (LLMs) primarily focus on architectural modifications or optimizer adjustments. However, these approaches lack systematic optimization of weight patterns during training. Weight pattern refers to the distribution and relative magnitudes of weight parameters in a neural network. To address this issue, we propose a Weight Scaling method called WISCA to enhance training efficiency and model quality by strategically improving neural network weight patterns—without changing network structures. By rescaling weights while preserving model outputs, WISCA indirectly optimizes the model’s training trajectory. Experiments demonstrate that WISCA significantly improves convergence quality (measured by generalization capability and loss reduction), particularly in LLMs with Grouped Query Attention (GQA) architectures and LoRA fine-tuning tasks. Empirical results show 5.6% average improvement on zero-shot validation tasks and 2.12% average reduction in training perplexity across multiple architectures.
Optimizing Native Sparse Attention with Latent Attention and Local Global Alternating Strategies
Yuxuan Hu | Jianchao Tan | Jiaqi Zhang | Wen Zan | Pingwei Sun | Yifan Lu | Xunliang Cai | Jing Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Yuxuan Hu | Jianchao Tan | Jiaqi Zhang | Wen Zan | Pingwei Sun | Yifan Lu | Xunliang Cai | Jing Zhang
Findings of the Association for Computational Linguistics: ACL 2026
In this work, we conduct a systematic analysis of Native Sparse Attention (NSA) and propose targeted improvements that enhance long-context modeling. A key insight is that alternating between local (sliding-window) and global (compression/selective) attention across layers, rather than using fixed patterns, enables more effective propagation of long-range dependencies and substantially boosts performance on long-sequence tasks. Meanwhile, we further refine NSA’s branches with Latent Attention that the sliding-window branch is enhanced with Multi-head Latent Attention (MLA) while compression and selective branches adopt Group-head Latent Attention (GLA). These changes reduce KV-cache memory by 50% versus NSA while improving the model’s common-sense reasoning and long-text understanding capabilities. Experiments on models from 340M to 1.3B parameters (trained on 15B and 100B tokens) show our method matches or exceeds full attention and native sparse attention in both common-sense reasoning and long-context understanding tasks.
FG2-GDN: Enhancing Long-Context Gated Delta Networks with Doubly Fine-Grained Control
Pingwei Sun | Yuxuan Hu | Jianchao Tan | Xue Wang | Jiaqi Zhang | Yifan Lu | Yerui Sun | Yuchen Xie | Xunliang Cai
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Pingwei Sun | Yuxuan Hu | Jianchao Tan | Xue Wang | Jiaqi Zhang | Yifan Lu | Yerui Sun | Yuchen Xie | Xunliang Cai
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Linear attention mechanisms have emerged as promising alternatives to softmax attention, offering linear-time complexity during inference. Recent advances such as Gated DeltaNet (GDN) and Kimi Delta Attention (KDA) have demonstrated that the delta rule (an online gradient descent update) enables superior associative recall compared to simple additive updates. While KDA refined the coarse head-wise decay gate into channel-wise decay, the learning rate 𝛽t in the delta update remains a scalar, limiting the model’s capacity for dimension-specific adaptation. We introduce FG2-GDN, which replaces the scalar 𝛽t with a channel-wise vector in a manner analogous to the transition from SGD to per-coordinate adaptive optimizers such as AdaGrad and Adam. We further propose FG2-GDN+, which decouples the scaling for keys and values, enabling independent control of erasure strength and write strength. Experiments on synthetic and real-world benchmarks show that FG2-GDN and its variant improve associative recall and long-context understanding over GDN and KDA, with comparable computational efficiency.