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2505.17353 2026-05-15 cs.CV cs.AI cs.LG eess.IV

Dual Ascent Diffusion for Inverse Problems

Minseo Kim, Axel Levy, Gordon Wetzstein

发表机构 * Stanford University(斯坦福大学)

AI总结 本文研究了如何利用扩散模型解决逆问题中的病态问题,提出了一种基于对偶上升优化框架的新方法。该方法在图像恢复任务中表现出更优的图像质量、更强的噪声鲁棒性以及更快的计算速度,同时能更真实地反映观测数据。该工作为逆问题求解提供了更高效且准确的解决方案。

Comments Project page: https://soniaminseokim.github.io/ddiff/

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英文摘要

Ill-posed inverse problems are fundamental in many domains, ranging from astrophysics to medical imaging. Emerging diffusion models provide a powerful prior for solving these problems. Existing maximum-a-posteriori (MAP) or posterior sampling approaches, however, rely on different computational approximations, leading to inaccurate or suboptimal samples. To address this issue, we introduce a new approach to solving MAP problems with diffusion model priors using a dual ascent optimization framework. Our framework achieves better image quality as measured by various metrics for image restoration problems, it is more robust to high levels of measurement noise, it is faster, and it estimates solutions that represent the observations more faithfully than the state of the art.

2502.16060 2026-05-15 cs.LG cs.AI eess.SP

Tokenizing Single-Channel EEG with Time-Frequency Motif Learning

Jathurshan Pradeepkumar, Xihao Piao, Zheng Chen, Jimeng Sun

发表机构 * University of Illinois Urbana-Champaign(伊利诺伊大学厄巴纳-香槟分校) SANKEN, Osaka University(大阪大学SANKEN)

AI总结 本文提出了一种名为TFM-Tokenizer的新颖EEG分词框架,通过从单通道脑电图信号中学习时间-频率模式词汇并将其编码为离散标记,解决了EEG分词这一重要难题。该方法采用双路径架构与时间-频率掩码机制,能够生成鲁棒的模式表示,并适用于多种下游模型,包括轻量级变压器和现有基础模型。实验表明,该分词器在多个EEG基准数据集上显著提升了性能,具有更好的泛化能力和设备适应性。

Comments Accepted to ICLR 2026

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英文摘要

Foundation models are reshaping EEG analysis, yet an important problem of EEG tokenization remains a challenge. This paper presents TFM-Tokenizer, a novel tokenization framework that learns a vocabulary of time-frequency motifs from single-channel EEG signals and encodes them into discrete tokens. We propose a dual-path architecture with time-frequency masking to capture robust motif representations, and it is model-agnostic, supporting both lightweight transformers and existing foundation models for downstream tasks. Our study demonstrates three key benefits: Accuracy: Experiments on four diverse EEG benchmarks demonstrate consistent performance gains across both single- and multi-dataset pretraining settings, achieving up to $11\%$ improvement in Cohen's Kappa over strong baselines. Generalization: Moreover, as a plug-and-play component, it consistently boosts the performance of diverse foundation models, including BIOT and LaBraM. Scalability: By operating at the single-channel level rather than relying on the strict 10-20 EEG system, our method has the potential to be device-agnostic. Experiments on ear-EEG sleep staging, which differs from the pretraining data in signal format, channel configuration, recording device, and task, show that our tokenizer outperforms baselines by $14\%$. A comprehensive token analysis reveals strong class-discriminative, frequency-aware, and consistent structure, enabling improved representation quality and interpretability. Code is available at https://github.com/Jathurshan0330/TFM-Tokenizer.

2502.00270 2026-05-15 cs.LG cs.AI stat.ML

DUET: Optimizing Training Data Mixtures via Feedback from Unseen Evaluation Tasks

Zhiliang Chen, Gregory Kang Ruey Lau, Chuan-Sheng Foo, Bryan Kian Hsiang Low

发表机构 * National University of Singapore(新加坡国立大学) Agency for Research, Science, Technology and Research (A*STAR)(研究、科技与研发机构)

AI总结 本文研究了如何在未知的下游评估任务下优化大型语言模型的训练数据混合问题。由于实际任务数据往往不可见,传统数据选择方法难以适用,作者提出了一种基于反馈的优化方法DUET,结合影响函数与贝叶斯优化,实现了无需任务数据先验知识的全局到局部的数据混合优化。实验表明,DUET在多种语言任务中优于现有方法,展示了其在未知任务设置下的有效性。

Comments Accepted to ICLR 2026 main conference

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英文摘要

The performance of an LLM depends heavily on the relevance of its training data to the downstream evaluation task. However, in practice, the data involved in an unseen evaluation task is often unknown (e.g., conversations between an LLM and a user are end-to-end encrypted). Hence, it is unclear what data are relevant for fine-tuning the LLM to maximize its performance on the specific unseen evaluation task. Instead, one can only deploy the LLM on the unseen task to gather multiple rounds of feedback on how well the model performs (e.g., user ratings). This novel setting offers a refreshing perspective towards optimizing training data mixtures via feedback from an unseen evaluation task, which prior data mixing and selection works do not consider. Our paper presents DUET, a novel global-to-local algorithm that interleaves influence function as a data selection method with Bayesian optimization to optimize data mixture via feedback from a specific unseen evaluation task. By analyzing DUET's cumulative regret, we theoretically show that DUET converges to the optimal training data mixture for an unseen task even without any data knowledge of the task. Finally, our experiments across a variety of language tasks demonstrate that DUET outperforms existing data selection and mixing methods in the unseen-task setting.

2411.18104 2026-05-15 cs.CL cs.AI cs.LG

Training and Evaluating Language Models with Template-based Data Generation

Yifan Zhang

发表机构 * University of California Los Angeles(加州大学洛杉矶分校)

AI总结 本文针对大语言模型在复杂多步骤推理任务(如数学问题求解)中的不足,提出了一种基于模板的数据生成方法(TDG),利用前沿大模型GPT-4自动生成参数化元模板,从而合成大量高质量的问题与解答。研究构建了包含700多万道小学数学题的TemplateMath Part I:TemplateGSM数据集,每个问题均配有可编程验证的解法,有效解决了数据稀缺问题,并为模型对齐提供了基于可验证奖励的强化学习机制,推动了具备强大推理能力的新一代大语言模型的发展。

Comments Published in ICLR 2025 DATA-FM Workshop. Project Page: https://github.com/iiis-ai/TemplateMath

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英文摘要

The rapid advancement of large language models (LLMs) such as GPT-3, PaLM, and Llama has significantly transformed natural language processing, showcasing remarkable capabilities in understanding and generating language. However, a fundamental bottleneck persists: these models often struggle with tasks requiring complex, multi-step reasoning, particularly in mathematical problem-solving. This deficiency stems from the critical scarcity of large-scale, high-quality, domain-specific datasets necessary for cultivating sophisticated reasoning abilities. To overcome this challenge, we introduce Template-based Data Generation (TDG), a novel and scalable paradigm that harnesses frontier LLMs (GPT-4) to automatically generate parameterized meta-templates, which in turn synthesize a virtually infinite stream of high-quality problems and solutions. Using this paradigm, we create TemplateMath Part I: TemplateGSM, a foundational dataset of over 7 million synthetically generated grade school math problems. Each problem is accompanied by a programmatically verifiable solution, offering an unprecedented level of quality at scale. This resource not only resolves the data scarcity issue for supervised fine-tuning but also provides a robust mechanism for model alignment through Reinforcement Learning with Verifiable Rewards (RLVR). Our approach elevates data augmentation by leveraging GPT-4 to generate meta-templates, ensuring diverse and complex problem structures. By providing a scalable solution to the data and verification bottleneck, TDG and TemplateGSM pave the way for a new generation of LLMs with powerful, reliable reasoning skills.

2410.06431 2026-05-15 cs.LG

Functional-level Uncertainty Quantification for Calibrated Fine-tuning on LLMs

Ruijia Niu, Dongxia Wu, Rose Yu, Yi-An Ma

发表机构 * Department of Computer Science and Engineering, University of California San Diego(加州大学圣地亚哥分校计算机科学与工程系)

AI总结 本文研究了大语言模型在微调过程中不确定性量化的问题,针对现有方法在有限适配数据下容易过度自信的缺陷,提出了一种基于功能层面的不确定性量化方法UQ4CT。该方法通过混合专家微调框架,在训练过程中引入校准损失,使模型的功能层面置信度与预测正确性对齐,从而提升模型的校准性能。实验表明,UQ4CT在多个基准任务中显著降低了预期校准误差,同时保持了较高的准确率,并在分布偏移情况下表现出更强的鲁棒性。

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英文摘要

Accurate uncertainty quantification in large language models (LLMs) is essential for reliable confidence estimation, yet fine-tuned LLMs often become overconfident under limited adaptation data. Existing uncertainty methods for PEFT-based LLMs are largely post hoc, estimating uncertainty after fine-tuning rather than improving how adapters specialize to task-specific input-output relationships. We propose Functional-Level Uncertainty Quantification for Calibrated Fine-Tuning (UQ4CT), which calibrates uncertainty over the functional space induced by prompt-dependent mixtures of LoRA experts. UQ4CT implements this perspective through a mixture-of-experts fine-tuning framework, where a calibration loss aligns functional-level confidence with predictive correctness during training. Across four multiple-choice benchmarks and two open-ended generative QA tasks, UQ4CT reduces Expected Calibration Error (ECE) by over $25\%$ while preserving high accuracy. Under distribution shift, UQ4CT maintains superior calibration and competitive accuracy, demonstrating improved reliability and generalization for fine-tuned LLMs.

2605.15172 2026-05-15 cs.CR cs.CL

MetaBackdoor: Exploiting Positional Encoding as a Backdoor Attack Surface in LLMs

Rui Wen, Mark Russinovich, Andrew Paverd, Jun Sakuma, Ahmed Salem

发表机构 * Institute of Science Tokyo(东京科学研究院) Microsoft Azure(微软Azure) Microsoft Security Response Center(微软安全响应中心)

AI总结 本文提出了一种新型的后门攻击方法MetaBackdoor,利用大语言模型中的位置编码作为触发机制,无需修改输入文本内容即可激活后门。研究发现,基于位置信息的触发器能够有效激活隐蔽的后门行为,使模型在满足特定长度条件时泄露敏感信息或执行恶意操作。该方法扩展了大语言模型后门攻击的威胁模型,揭示了位置编码这一此前被忽视的攻击面,为防御策略的设计提出了新的挑战。

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英文摘要

Backdoor attacks pose a serious security threat to large language models (LLMs), which are increasingly deployed as general-purpose assistants in safety- and privacy-critical applications. Existing LLM backdoors rely primarily on content-based triggers, requiring explicit modification of the input text. In this work, we show that this assumption is unnecessary and limiting. We introduce MetaBackdoor, a new class of backdoor attacks that exploits positional information as the trigger, without modifying textual content. Our key insight is that Transformer-based LLMs necessarily encode token positions to process ordered sequences. As a result, length-correlated positional structure is reflected in the model's internal computation and can be used as an effective non-content trigger signal. We demonstrate that even a simple length-based positional trigger is sufficient to activate stealthy backdoors. Unlike prior attacks, MetaBackdoor operates on visibly and semantically clean inputs and enables qualitatively new capabilities. We show that a backdoored LLM can be induced to disclose sensitive internal information, including proprietary system prompts, once a length condition is satisfied. We further demonstrate a self-activation scenario, where normal multi-turn interaction can move the conversation context into the trigger region and induce malicious tool-call behavior without attacker-supplied trigger text. In addition, MetaBackdoor is orthogonal to content-based backdoors and can be composed with them to create more precise and harder-to-detect activation conditions. Our results expand the threat model of LLM backdoors by revealing positional encoding as a previously overlooked attack surface. This challenges defenses that focus on detecting suspicious text and highlights the need for new defense strategies that explicitly account for positional triggers in modern LLM architectures.

2605.15154 2026-05-15 stat.ML cs.LG

RoSHAP: A Distributional Framework and Robust Metric for Stable Feature Attribution

Lanxin Xiang, Liang Shi, Youhui Ye, Boyu Jiang, Dawei Zhou, Feng Guo

发表机构 * Department of Statistics(统计学系) Virginia Tech(弗吉尼亚理工大学) Transportation Institute(交通运输研究所) Department of Computer Science(计算机科学系)

AI总结 本文提出了一种名为RoSHAP的分布框架和鲁棒度量方法,用于实现更稳定的特征归因分析。该方法基于SHAP值,通过引导重采样和核密度估计建模特征归因分数的分布,并在温和正则条件下证明其聚合值渐近服从高斯分布,从而降低了分布估计的计算成本。RoSHAP不仅提升了特征排名的稳定性,还在模拟和实际数据实验中表现出优于传统单次归因方法的性能,同时使用更少的特征即可达到与全特征模型相当的预测效果。

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Feature attribution analysis is critical for interpreting machine learning models and supporting reliable data-driven decisions. However, feature attribution measures often exhibit stochastic variation: different train--test splits, random seeds, or model-fitting procedures can produce substantially different attribution values and feature rankings. This paper proposes a framework for incorporating stochastic nature of feature attribution and a robust attribution metric, RoSHAP, for stable feature ranking based on the SHAP metric. The proposed framework models the distribution of feature attribution scores and estimates it through bootstrap resampling and kernel density estimation. We show that, under mild regularity conditions, the aggregated feature attribution score is asymptotically Gaussian, which greatly reduces the computational cost of distribution estimation. The RoSHAP summarizes the distribution of SHAP into a robust feature-ranking criterion that simultaneously rewards features that are active, strong, and stable. Through simulations and real-data experiments, the proposed framework and RoSHAP outperform standard single-run attribution measures in identifying signal features. In addition, models built using RoSHAP-selected features achieve predictive performance comparable to full-feature models while using substantially fewer predictors. The proposed RoSHAP approach improves the stability and interpretability of machine learning models, enabling reliable and consistent insights for analysis.

2605.15127 2026-05-15 cs.HC cs.AI

Understanding How International Students in the U.S. Are Using Conversational AI to Support Cross-Cultural Adaptation

Laleh Nourian, Anisa Callis, Stephanie Patterson, Jadeline Miao, Jamison Heard, Garreth W. Tigwell

发表机构 * Rochester Institute of Technology(罗切斯特理工学院) School of Information(信息学院)

AI总结 本文研究了在美国留学的国际学生如何使用对话式人工智能来支持跨文化适应。通过调查和访谈,研究揭示了国际学生在面临文化适应挑战时对AI工具的使用模式、动机及局限性。研究发现,AI被视为应对即时问题的“急救工具”,但学生也期望其能发展为长期支持伙伴。研究为设计更贴合国际学生需求的AI支持系统提供了重要建议。

Comments 33 pages, single column. 4 figures, 9 tables

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英文摘要

Moving to a new culture and adapting to a new life, as an international student, can be a stressful experience. In the US, international students face unique overlapping challenges, yet the current support ecosystem, including university support systems and informal social networks, remains largely fragmented. While conversational AI has emerged as a tool used by many (e.g., generative AI chatbots like ChatGPT and Google Gemini), we do not have a clear understanding of how international students adopt and perceive these technologies as support tools. We conducted a survey study (n=60) to map the relationship between international students' challenges and AI adoption patterns, followed by an interview study with 14 participants to identify the underlying motivations and boundaries of use. Our findings show that AI is perceived as a first-aid tool for immediate challenges, however, there is an interest in transforming AI from a tool for short-term help into a long-term support companion. By identifying where and how AI can provide long-term support, and where it is insufficient, we contribute recommendations for creating AI-powered support tailored to the unique needs of international students.

2605.15085 2026-05-15 stat.ML cs.LG stat.AP stat.ME

From Data to Action: Accelerating Refinery Optimization with AI

Dániel Pfeifer, Ábrahám Papp, Tibor Bernáth, Tamás Zoltán Varga, Márk Czifra, Botond Szilágyi, Edith Alice Kovács

发表机构 * Budapest University of Technology and Economics(布达佩斯技术与经济大学)

AI总结 本文研究了如何利用人工智能加速炼油厂优化过程,针对线性规划(LP)方法在实际应用中面临的解释与应用难题,提出结合机器学习的方法以提升决策支持。核心方法包括改进的异常检测工具和高维数据处理策略,有效识别了炼油厂调度与规划中的业务机会与数据供应错误,为优化结果的可信度提供了新的洞察。

Comments 34 pages, 17 figures

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Nowadays refinery optimization utilizes sheer amounts of data, which can be handled with modern Linear Programming (LP) software, but the interpreting and applying the results remains challenging. Large petrochemical companies use massive models, with hundreds of thousands of input matrix elements. The LP solution is mathematically correct, but simplifications are made in the model, and data supply errors may occur. Therefore, further insight is needed to trust the results. The LP solver does not have a memory, so additional understanding could be gained by analyzing historical data and comparing it to the current plan. As such, machine learning approaches were suggested to support decision making based on the LP solution. Among these, Anomaly Detection tools are proposed to be used in tandem with the LP output. A transformed version of the popular ECOD methodology is applied. New methods are proposed to handle high-dimensional data: choosing the most informative pairs. Then, this is used alongside two 2D Anomaly Detection algorithms, revealing several business opportunities and data supply errors in the MOL refinery scheduling and planning architecture.

2605.15082 2026-05-15 stat.ML cs.LG math.ST stat.TH

Average Gradient Outer Product in kernel regression provably recovers the central subspace for multi-index models

Libin Zhu, Damek Davis, Dmitriy Drusvyatskiy, Maryam Fazel

发表机构 * Department of Mathematics, University of Washington, Seattle, WA 98195(华盛顿大学数学系,华盛顿州西雅图98195) Wharton Department of Statistics and Data Science, University of Pennsylvania, Philadelphia, PA 19104, USA(宾夕法尼亚大学沃顿统计与数据科学系,美国费城19104) Department of Mathematics, U. Washington, Seattle, WA 98195(华盛顿大学数学系,华盛顿州西雅图98195) Department of Electrical & Computer Engineering, University of Washington, Seattle, WA 98195, and Amazon, Inc(华盛顿大学电气与计算机工程系,华盛顿州西雅图98195,亚马逊公司)

AI总结 本文研究了在样本数量少于精确预测所需的情况下,如何通过学习预测器发现数据中的低维结构。具体来说,考虑从有限数据对中恢复多指标多项式模型 $f^*(x)=h(Ux)$ 的问题,其中输入仅通过未知的 $r$ 维中心子空间的投影来影响输出。作者提出了一种简单方法:拟合核岭回归(KRR)并计算拟合预测器的平均梯度外积(AGOP),证明其前 $r$ 个特征向量可准确恢复该子空间,即使预测误差仍较大时也成立。研究还表明,当目标函数的低阶部分包含所有预测相关方向时,子空间恢复所需的样本量远低于精确预测所需的样本量,揭示了预测与表示之间的差异。

Comments 95 pages, 12 figures

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英文摘要

We study a prototypical situation when a learned predictor can discover useful low-dimensional structure in data, while using fewer samples than are needed for accurate prediction. Specifically, we consider the problem of recovering a multi-index polynomial $f^*(x)=h(Ux)$, with $U\in\mathbb{R}^{r\times d}$ and $r\ll d$, from finitely many data/label pairs. Importantly, the target function depends on input $x$ only through the projection onto an unknown $r$-dimensional central subspace. The algorithm we analyze is appealingly simple: fit kernel ridge regression (KRR) to the data and compute the Average Gradient Outer Product (AGOP) from the fitted predictor. Our main results show that under reasonable assumptions the top $r$-dimensional eigenspace of AGOP provably recovers the central subspace, even in regimes when the prediction error remains large. Specifically, if the target function $f^*$ has degree $p^*$, it is known that $n\asymp d^{p^*}$ samples are necessary for KRR to achieve accurate prediction. In contrast, we show that if a low degree $p$ component of $f^*$ already carries all relevant directions for prediction, subspace recovery occurs in the much lower sample regime $n\asymp d^{p+δ}$ for any $δ\in(0,1)$. Our results thus demonstrate a separation between prediction and representation, and provide an explanation for why iterative kernel methods such as Recursive Feature Machines (RFM) can be sample-efficient in practice.

2605.15058 2026-05-15 cs.NE cs.AI

NeuroTrain: Surveying Local Learning Rules for Spiking Neural Networks with an Open Benchmarking Framework

Alessio Caviglia, Filippo Marostica, Roberta Bardini, Alessandro Savino, Stefano Di Carlo

发表机构 * Politecnico di Torino, Control and Computer Engineering Department(托里尼理工大学控制与计算机工程系)

AI总结 本文综述了脉冲神经网络(SNN)训练算法的最新进展,系统梳理了包括替代梯度反向传播、局部学习规则、生物启发可塑性机制等在内的多种方法,并提出了一个统一的分类体系。为支持可复现的研究,作者开发了开源框架NeuroTrain,实现了多种典型算法,提供了统一、模块化且可扩展的基准测试平台。该工作整合了分散的文献资源,明确了当前挑战与未来研究方向,为高效、可扩展的SNN训练提供了重要参考。

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英文摘要

The rapid expansion of spiking neural networks (SNNs) has led to a proliferation of training algorithms that differ widely in biological inspiration, computational structure, and hardware suitability. Despite this progress, the field lacks a unified, fine-grained taxonomy that systematically organizes these approaches and clarifies their conceptual relationships. This survey provides a comprehensive taxonomy of SNN training algorithms, spanning surrogate-gradient backpropagation, local and three-factor learning rules, biologically inspired plasticity mechanisms, ANN-to-SNN conversion pipelines, and non-standard optimization strategies. We analyze each class in terms of its computational principles, learning signals, and locality properties. To support reproducible research, we release NeuroTrain, an open-source snnTorch-based framework that implements a representative set of these algorithms within a unified, modular, and extendable framework, enabling consistent benchmarking across datasets, architectures, and training regimes. By consolidating fragmented literature and providing a reusable benchmarking framework, this survey identifies common patterns, highlights open challenges, and outlines promising directions for future work on scalable, efficient SNN training.

2605.15032 2026-05-15 eess.SP cs.LG

Multi-Block Attention for Efficient Channel Estimation in IRS-Assisted mmWave MIMO

Mehrdad Momen-Tayefeh, Mehrshad Momen-Tayefeh, Maryam Sabbaghian

发表机构 * School of Electrical and Computer Engineering, University of Tehran(德黑兰理工大学电子与计算机工程学院) Department of Computer Engineering, Sharif University of Technology(谢赫·伊斯兰技术大学计算机工程系)

AI总结 本文研究了智能反射表面(IRS)辅助毫米波MIMO系统中的高效信道估计问题,提出了基于深度学习的多块注意力(MBA)框架,用于降低训练开销并提升估计精度。该方法通过选择性关闭IRS元素并结合两阶段网络结构,分别进行空间相关性恢复和噪声抑制,有效减少了信道估计中的误差传播。实验表明,MBA方法在保持低计算复杂度的同时,显著降低了导频开销并提升了信道估计性能。

Journal ref IEEE Transactions on Communications, vol. 73, no. 12, pp. 13891-13903, Dec. 2025

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英文摘要

Intelligent Reflecting Surfaces (IRSs) are a promising technology for enhancing the spectral and energy efficiency of millimeter-wave (mmWave) multiple-input multiple-output (MIMO) systems. In these systems, accurate channel estimation remains challenging due to the passive nature of IRS elements and the high pilot overhead in large-scale deployments. This paper presents a deep learning-based Multi-Block Attention (MBA) framework for efficient cascaded channel estimation in IRS-assisted mmWave MIMO systems that utilize orthogonal frequency division multiplexing (OFDM). First, we show the optimality of the discrete Fourier transform (DFT) and Hadamard matrices as phase configurations for least squares (LS) estimation. To reduce training overhead, we selectively deactivate IRS elements and compensate for induced feature loss using a two-stage architecture: (i) a Convolutional Attention Network (CAN) for spatial correlation recovery and (ii) a Complex Multi-Convolutional Network (CMN) for noise suppression. The MBA architecture mitigates error propagation through attention-guided feature refinement and denoising. Simulation results indicate that the MBA method reduces pilot overhead by up to 87% compared to the LS estimator. Additionally, at signal-to-noise ratios of 10 dB, our proposed method achieves approximately 51% lower normalized mean squared error (NMSE) than leading methods. It also maintains low computational complexity and adapts effectively to various propagation environments.

2605.15030 2026-05-15 cs.CR cs.AI

WARD: Adversarially Robust Defense of Web Agents Against Prompt Injections

Tri Cao, Yulin Chen, Hieu Cao, Yibo Li, Khoi Le, Thong Nguyen, Yuexin Li, Yufei He, Yue Liu, Shuicheng Yan, Bryan Hooi

发表机构 * National University of Singapore(新加坡国立大学) University of Science(科学大学) Vietnam National University, Ho Chi Minh City(越南国家大学,胡志明市)

AI总结 本文提出WARD,一种针对网络代理的对抗性鲁棒防御方法,用于抵御HTML内容或视觉界面中的提示注入攻击。WARD基于大规模数据集WARD-Base和专门设计的攻击数据集WARD-PIG进行训练,并引入了A3T自适应对抗训练框架,通过记忆驱动的攻击者与防御者共进化过程提升模型鲁棒性。实验表明,WARD在分布外基准上实现了接近完美的召回率,保持较低的误报率,并在分布偏移和针对性攻击下仍表现出高效稳定的防御性能。

Comments Code and models: https://github.com/caothientri2001vn/WARD-WebAgent

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英文摘要

Web agents can autonomously complete online tasks by interacting with websites, but their exposure to open web environments makes them vulnerable to prompt injection attacks embedded in HTML content or visual interfaces. Existing guard models still suffer from limited generalization to unseen domains and attack patterns, high false positive rates on benign content, reduced deployment efficiency due to added latency at each step, and vulnerability to adversarial attacks that evolve over time or directly target the guard itself. To address these limitations, we propose WARD (Web Agent Robust Defense against Prompt Injection), a practical guard model for secure and efficient web agents. WARD is built on WARD-Base, a large-scale dataset with around 177K samples collected from 719 high-traffic URLs and platforms, and WARD-PIG, a dedicated dataset designed for prompt injection attacks targeting the guard model. We further introduce A3T, an adaptive adversarial attack training framework that iteratively strengthens WARD through a memory-based attacker and guard co-evolution process. Extensive experiments show that WARD achieves nearly perfect recall on out-of-distribution benchmarks, maintains low false positive rates to preserve agent utility, remains robust against guard-targeted and adaptive attacks under substantial distribution shifts, and runs efficiently in parallel with the agent without introducing additional latency.

2605.15026 2026-05-15 cs.OS cs.AI cs.PF

SemaTune: Semantic-Aware Online OS Tuning with Large Language Models

Georgios Liargkovas, Mihir Nitin Joshi, Hubertus Franke, Kostis Kaffes

发表机构 * Columbia University(哥伦比亚大学) IBM Research(IBM研究院)

AI总结 SemaTune 是一种基于大语言模型的语义感知在线操作系统调优框架,旨在提升长期运行服务的性能。该方法通过整合系统参数、监控数据、配置历史等信息构建决策上下文,结合快速和慢速反馈回路进行调优,并在更新前进行类型验证,从而在保证模型开销和系统稳定性的同时,实现对操作系统控制语义的理解。实验表明,SemaTune 在多个基准测试中显著优于传统方法,提升了稳定阶段的性能表现,并有效避免了系统性能的严重下降。

Comments 17 pages, 12 figures

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Online OS tuning can improve long-running services, but existing controllers are poorly matched to live hosts. They treat scheduler, power, memory, and I/O controls as black-box variables and optimize a scalar reward. This view ignores cross-knob policy structure, breaks down when application metrics are unavailable, and can send a running service into degraded regions that persist after the bad setting is removed. We present SemaTune, a host-side framework for steady-state OS tuning with bounded language-model guidance. SemaTune turns knob schemas, telemetry, current configuration, recent action--response history, and retrieved prior runs into a compact decision context. A fast loop proposes low-latency updates, a slower loop periodically revises the search strategy, and every proposed change passes through typed validation before reaching kernel or sysctl interfaces. This lets the controller reason about OS-control meaning and indirect performance signals while keeping model cost, latency, and authority constrained. We evaluate SemaTune on 13 live workloads from five benchmark suites while tuning up to 41 Linux parameters. Across the suite, SemaTune improves stable-phase performance by 72.5\% over default settings and by 153.3\% relative to the strongest non-LLM baseline. A 30-window session costs about \$0.20 in model calls. With only host-level metrics, SemaTune still outperforms baselines given direct application objectives by 93.7 percentage points, while avoiding severe degraded regions reached by structure-blind exploration.

2605.14983 2026-05-15 cs.GT cs.AI cs.CY cs.MA

Agreement, Diversity, and Polarization Indices for Approval Elections

Piotr Faliszewski, Jitka Mertlová, Krzysztof Sornat, Stanisław Szufa, Tomasz Wąs

发表机构 * AGH University of Kraków(克拉科夫AGH大学) Czech Technical University in Prague(布拉格捷克技术大学) University of Geneva(日内瓦大学) University of Oxford(牛津大学)

AI总结 本文研究了如何通过指数量化批准选举中选民之间的一致性、多样性和极化程度。提出了一系列归一化的指数,用于衡量选举中这些特征,并分析了它们的性质。研究还利用这些指数绘制了新的批准选举图谱,并比较了来自多个真实数据集的选举之间的异同。

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英文摘要

An index is a function that given an election outputs a value between 0 and 1, indicating the extent to which this election has a particular feature. We seek indices that capture agreement, diversity, and polarization among voters in approval elections, and that are normalized with respect to saturation. By the latter we mean that if two elections differ by the fraction of candidates approved by an average voter, but otherwise are of similar nature, then they should have similar index values. We propose several indices, analyze their properties, and use them to (a) derive a new map of approval elections, and (b) show similarities and differences between various real-life elections from Pabulib, Preflib and other sources.

2605.13338 2026-05-15 cs.CR cs.AI

Inducing Overthink: Hierarchical Genetic Algorithm-based DoS Attack on Black-Box Large Language Reasoning Models

Shuqiang Wang, Wei Cao, Jiaqi Weng, Jialing Tao, Licheng Pan, Hui Xue, Zhixuan Chu

发表机构 * The State Key Laboratory of Blockchain and Data Security, Zhejiang University(区块链与数据安全国家重点实验室,浙江大学) Alibaba Group(阿里巴巴集团)

AI总结 本文研究了大型推理模型(LRMs)在面对不完整或逻辑不一致输入时容易“过度思考”的漏洞,该行为会导致推理过程冗长且耗能,可能被用于发起拒绝服务(DoS)攻击。作者提出了一种基于分层遗传算法的黑盒攻击框架,通过系统性地扰动输入问题的逻辑结构,诱导模型产生更长的推理过程。实验表明,该方法在多个先进推理模型上显著放大了输出长度,并具有良好的迁移性,凸显了“过度思考”作为现代推理系统共有的潜在安全风险。

Comments Accepted at ICML 2026. Code available at: https://github.com/EndlessCao/Overthink-HGA

Journal ref Proceedings of the 43rd International Conference on Machine Learning (ICML 2026), PMLR 306, 2026

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Large Reasoning Models (LRMs) are increasingly integrated into systems requiring reliable multi-step inference, yet this growing dependence exposes new vulnerabilities related to computational availability. In particular, LRMs exhibit a tendency to "overthink", producing excessively long and redundant reasoning traces, when confronted with incomplete or logically inconsistent inputs. This behavior significantly increases inference latency and energy consumption, forming a potential vector for denial-of-service (DoS) style resource exhaustion. In this work, we investigate this attack surface and propose an automated black-box framework that induces overthinking in LRMs by systematically perturbing the logical structure of input problems. Our method employs a hierarchical genetic algorithm (HGA) operating on structured problem decompositions, and optimizes a composite fitness function designed to maximize both response length and reflective overthinking markers. Across four state-of-the-art reasoning models, the proposed method substantially amplifies output length, achieving up to a 26.1x increase on the MATH benchmark and consistently outperforming benign and manually crafted missing-premise baselines. We further demonstrate strong transferability, showing that adversarial inputs evolved using a small proxy model retain high effectiveness against large commercial LRMs. These findings highlight overthinking as a shared and exploitable vulnerability in modern reasoning systems, underscoring the need for more robust defenses.

2512.16768 2026-05-15 stat.ML cs.LG math.PR

On The Hidden Biases of Flow Matching Samplers

Soon Hoe Lim

发表机构 * KTH Royal Institute of Technology(皇家理工学院) Nordita(北欧理论物理研究所) Stockholm University(斯德哥尔摩大学)

AI总结 本文研究了流匹配(Flow Matching)采样器在有限样本情况下的隐藏偏差问题。通过将总体期望替换为样本平均,并用有限样本替代目标分布,作者提出了一种经验流匹配模型的层次结构。针对仿射条件流,文中推导了精确的经验最小化解,并识别出一种平滑插值机制,使得终端分布恰好为核混合估计量。研究揭示了经验流匹配中的多重偏差来源,包括目标分布替换带来的统计目标变化、经验最小化解可能不是梯度场,以及边际路径无法唯一确定粒子动力学等问题。

Comments 41 pages

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Flow matching (FM) constructs continuous-time ODE samplers by prescribing probability paths between a base distribution and a target distribution. In this note, we study FM through the lens of finite-sample plug-in estimation. In addition to replacing population expectations by sample averages, one may replace the target distribution itself by a finite-sample surrogate, ranging from the empirical measure to a smoothed estimator. This viewpoint yields a natural hierarchy of empirical FM models. For affine conditional flows, we derive the exact empirical minimizer and identify a smoothed plug-in regime in which the terminal law is exactly a kernel-mixture estimator. This plug-in perspective clarifies several coupled finite-sample biases of empirical FM. First, replacing the target law by a finite-sample surrogate changes the statistical target. Second, the empirical minimizer is generally not a gradient field, even when each conditional flow is. Third, a fixed empirical marginal path does not determine a unique particle dynamics: one may add extra vector fields whose probability flux has zero divergence without changing the marginal path. For Gaussian affine conditional paths, we give explicit families of such flux-null corrections. Finally, the source distribution provides a primary mechanism controlling upper tails of kinetic energy. In particular, Gaussian bases yield exponential upper-tail bounds for instantaneous and integrated kinetic energies, whereas polynomially tailed bases yield corresponding polynomial upper-tail bounds.

2502.03672 2026-05-15 physics.comp-ph cs.LG cs.NA math.NA

Physically consistent predictive reduced-order modeling by enhancing Operator Inference with state constraints

Hyeonghun Kim, Boris Kramer

发表机构 * Department of Mechanical and Aerospace Engineering, University of California San Diego, CA, United States(机械与航空航天工程系,加州大学圣地亚哥分校,加州,美国)

AI总结 本文提出了一种增强算子推断方法的新策略,通过在降阶模型中嵌入状态约束,以提高对复杂多物理系统(如焦炭燃烧)的预测稳定性与物理一致性。该方法引入基于关键性能指标的正则化超参数选择方式,并在实际应用中展示了其在稳定性、准确性和外推能力方面的优越性。

Comments 33 pages, 13 figures

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Numerical simulations of complex multiphysics systems, such as char combustion considered herein, yield numerous state variables that inherently exhibit physical constraints. This paper presents a new approach to augment Operator Inference -- a methodology within scientific machine learning that enables learning from data a low-dimensional representation of a high-dimensional system governed by nonlinear partial differential equations -- by embedding such state constraints in the reduced-order model predictions. In the model learning process, we propose a new way to choose regularization hyperparameters based on a key performance indicator. Since embedding state constraints improves the stability of the Operator Inference reduced-order model, we compare the proposed state constraints-embedded Operator Inference with the standard Operator Inference and other stability-enhancing approaches. For an application to char combustion, we demonstrate that the proposed approach yields state predictions superior to the other methods regarding stability and accuracy. It extrapolates over 200\% past the training regime while being computationally efficient and physically consistent.

2412.14291 2026-05-15 math.OC cs.LG stat.ML

Projected gradient methods for nonconvex and stochastic smooth optimization: new complexities and auto-conditioned stepsizes

Guanghui Lan, Tianjiao Li, Yangyang Xu

发表机构 * School of Industrial and Systems Engineering, Georgia Institute of Technology(工业与系统工程学院,佐治亚理工学院) Department of Mathematical Sciences, Rensselaer Polytechnic Institute(数学科学系,伦塞拉尔理工学院)

AI总结 本文提出了一类新的投影梯度(PG)方法,用于在凸紧集上最小化光滑但不一定凸的目标函数。研究引入了“自适应条件化”投影梯度(AC-PG)方法,在无需输入梯度的Lipschitz常数或进行线搜索的情况下,达到了与现有最佳方法相当的迭代复杂度。此外,文章将PG方法推广到随机优化场景,提出了随机投影梯度(SPG)和方差缩减随机梯度(VR-SPG)方法,并在不同Oracle设置下获得了新的复杂度界,同时为这些方法设计了自适应步长策略,保证了收敛性。

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We present a novel class of projected gradient (PG) methods for minimizing a smooth but not necessarily convex function over a convex compact set. We first provide a novel analysis of the constant-stepsize PG method, achieving the best-known iteration complexity for finding an approximate stationary point of the problem. We then develop an "auto-conditioned" projected gradient (AC-PG) variant that achieves the same iteration complexity without requiring the input of the Lipschitz constant of the gradient or any line search procedure. The key idea is to estimate the Lipschitz constant using first-order information gathered from the previous iterations, and to show that the error caused by underestimating the Lipschitz constant can be properly controlled. We then generalize the PG methods to the stochastic setting, by proposing a stochastic projected gradient (SPG) method and a variance-reduced stochastic gradient (VR-SPG) method, achieving new complexity bounds in different oracle settings. We also present auto-conditioned stepsize policies for both stochastic PG methods and establish comparable convergence guarantees.

2304.03641 2026-05-15 math.OC cs.LG cs.NA math.NA

A Block Coordinate Descent Method for Nonsmooth Composite Optimization under Orthogonality Constraints

Ganzhao Yuan

发表机构 * Shenzhen University of Advanced Technology (SUAT)(深圳先进技术大学(SUAT))

AI总结 本文研究了在正交约束下的非光滑复合优化问题,这类问题在统计学习和数据科学中有广泛应用,但因其目标函数非光滑且约束非凸,求解较为困难。作者提出了一种基于块坐标下降的新方法OBCD,每次迭代更新解矩阵的$k$行($k \geq 2$),通过求解一个小规模的非光滑优化子问题实现。该方法具有计算高效、可行性强的特点,并在理论上证明了其更新方案的完备性及收敛性,实验结果表明该方法优于现有方法。

Comments Future versions of this paper can be found at arXiv:2304.03641

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Nonsmooth composite optimization with orthogonality constraints has a wide range of applications in statistical learning and data science. However, this problem is challenging due to its nonsmooth objective and computationally expensive nonconvex constraints. In this paper, we propose a new approach called \textbf{OBCD}, which leverages block coordinate descent to address these challenges. \textbf{OBCD} is a feasible method with a small computational footprint. In each iteration, it updates \(k\) rows of the solution matrix, where \(k \geq 2\), by globally solving a small nonsmooth optimization problem under orthogonality constraints. We prove the completeness of the proposed update scheme, showing that row-wise orthogonal updates can reach any feasible point from any feasible initialization. We further prove that the limit points generated by \textbf{OBCD}, referred to as global block-\(k\) stationary points, offer stronger optimality than standard critical points. Furthermore, we show that \textbf{OBCD} finds an \(ε\)-block-\(k\) stationary point with an iteration complexity of \(\mathcal{O}(1/ε)\). Additionally, under the Kurdyka--Lojasiewicz (KL) inequality, we establish the non-ergodic convergence rate of \textbf{OBCD}. We also demonstrate how novel breakpoint search methods can be used to solve the subproblems arising in \textbf{OBCD}. Empirical results show that our approach consistently outperforms existing methods.

2012.14425 2026-05-15 cs.CR cs.LG

Vendor-Conditioned Contrastive Learning for Predicting Organizational Cyber Threat Targets

Benjamin M. Ampel

发表机构 * Department of Computer Science(计算机科学系) Georgia State University(佐治亚州立大学)

AI总结 该研究旨在识别网络攻击中针对的组织目标,提出了一种基于CySecBERT的对比学习框架TRACE,通过结合时间信息和供应商条件优化组织分类与表示学习,提升在时间分布偏移下的鲁棒性。研究利用涵盖九个漏洞数据库和黑客论坛的多源大规模语料库,构建了包含129,126个样本的七类组织数据集,在时间分布外测试中取得了97.00%的宏F1分数,显著优于多种经典机器学习和深度学习方法。

Comments 6 pages, 3 figures

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Cyberattacks cause billions of dollars in damage annually, with malicious hackers often sharing exploit code and techniques on underground forums. Identifying which organizations are targeted by these exploits is critical for proactive Cyber Threat Intelligence (CTI). To address that gap, we propose Temporal Representation and Classification of Exploits (TRACE), a vendor-conditioned contrastive learning framework built on CySecBERT that jointly optimizes organizational target classification and vendor-coherent representations while evaluating robustness under temporal distribution shift. Unlike prior work limited to small, single-source datasets, we leverage a large-scale, multi-source corpus spanning 9 exploit databases and hacker forums, comprising 352,866 posts collected over three decades, yielding a 129,126-sample dataset across seven organizational categories. In the temporal out-of-distribution evaluation, TRACE achieves macro F1=97.00\%, substantially outperforming 17 benchmark classical ML methods, deep learning with GloVe/FastText embeddings, and pretrained transformer models.

2605.14960 2026-05-15 cs.GR cs.CG cs.CV

Meschers: Geometry Processing of Impossible Objects

Ana Dodik, Isabella Yu, Kartik Chandra, Jonathan Ragan-Kelley, Joshua Tenenbaum, Vincent Sitzmann, Justin Solomon

发表机构 * MIT CSAIL(麻省理工学院计算机科学与人工智能实验室) MIT(麻省理工学院)

AI总结 本文研究了如何用计算机准确表示“不可能物体”——一类在现实中无法存在但人类可以感知的几何构造。传统方法通过切割或弯曲深度轴来实现,但会导致局部几何变化或光照处理困难,影响后续图形处理。为此,作者提出了一种名为 Meschers 的网格表示方法,基于离散外微分几何理论,能够有效支持渲染、光照和距离计算等应用,并实现了对不可能物体的逆向渲染,优于传统方法。

Journal ref ACM Trans. Graph. 44, 4, Article 70 (August 2025)

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Impossible objects, geometric constructions that humans can perceive but that cannot exist in real life, have been a topic of intrigue in visual arts, perception, and graphics, yet no satisfying computer representation of such objects exists. Previous work embeds impossible objects in 3D, cutting them or twisting/bending them in the depth axis. Cutting an impossible object changes its local geometry at the cut, which can hamper downstream graphics applications, such as smoothing, while bending makes it difficult to relight the object. Both of these can invalidate geometry operations, such as distance computation. As an alternative, we introduce Meschers, meshes capable of representing impossible constructions akin to those found in M.C. Escher's woodcuts. Our representation has a theoretical foundation in discrete exterior calculus and supports the use-cases above, as we demonstrate in a number of example applications. Moreover, because we can do discrete geometry processing on our representation, we can inverse-render impossible objects. We also compare our representation to cut and bend representations of impossible objects.

2605.14941 2026-05-15 eess.SP cs.HC cs.LG

nASR: An End-to-End Trainable Neural Layer for Channel-Level EEG Artifact Subspace Reconstruction in Real-Time BCI

Shantanu Sarkar, Jose L. Contreras-Vidal

发表机构 * Doctoral Candidate of Electrical & Computer Engineering, Univ. of Houston(电气与计算机工程博士候选人,休斯顿大学) Faculty of Electrical & Computer Engineering, Univ. of Houston(电气与计算机工程系,休斯顿大学)

AI总结 该研究提出了一种端到端可训练的神经网络层nASR,用于实时脑机接口(BCI)中的通道级EEG伪影子空间重构。传统ASR方法依赖固定阈值参数,易影响有效神经信号,而nASR通过引入两个可学习的阈值参数,实现了伪影检测与后续解码的联合优化,有效提升了信号质量与解码性能。实验表明,nASR在分类准确率和推理速度上均优于传统方法,适用于对延迟和性能要求较高的实时BCI应用。

Comments Preprint. Submitted to IEEE SMC 2026 (under review)

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Electroencephalogram (EEG) signals are highly susceptible to artifacts, resulting in a low signal-to-noise ratio which makes extraction of meaningful neural information challenging. Artifact Subspace Reconstruction (ASR) is one of the most widely used artifact filtering techniques in EEG-based BCI applications, owing to its real-time applicability. ASR reconstructs artifact-free signals by operating in Principal Component (PC) space within sliding windows. However, ASR performance is critically sensitive to its threshold parameter - an incorrect threshold risks removing task-relevant neural features alongside artifacts. Furthermore, since PCs are linear combinations of all channels, subspace reconstruction in PC space may alter the underlying data structure, potentially discarding essential neural information. To address these limitations, we propose nASR, a novel end-to-end trainable Keras layer that jointly optimizes artifact rejection and downstream decoding. nASR introduces two trainable threshold parameters: K, which governs artifact detection in PC variance space, and L, which quantifies eigen-spread to pinpoint the primary artifact--contributing channels, enabling selective channel-level reconstruction that preserves clean channel information. An ablation study comprising five model variants (m01 - m05), evaluated across two subjects from the BCI Competition IV Dataset 1, confirms that nASR variants consistently outperform traditional ASR on test classification metrics, while achieving a 6-8x reduction in inference time, making nASR a strong candidate for real-time BCI applications demanding both low latency and high decoding performance.

2605.14939 2026-05-15 physics.plasm-ph cs.LG

Real-time virtual circuits for plasma shape control via neural network emulators

Alasdair Ross, George K. Holt, Kamran Pentland, Adriano Agnello, Nicola C. Amorisco, Pedro Cavestany, Aran Garrod, Timothy Nunn, Charles Vincent, Graham McArdle

发表机构 * STFC Hartree Centre, Sci-Tech Daresbury(STFC哈特ree中心,科技达尔斯伯里) United Kingdom Atomic Energy Authority, Culham Campus(英国原子能局,库勒姆校园)

AI总结 该研究旨在解决托卡马克等离子体形状控制中实时调节多个强耦合参数的问题,提出了一种基于神经网络的虚拟电路(VC)实时生成方法。通过构建包含一百多万个模拟Grad–Shafranov平衡态的数据库,研究开发了能够实时生成状态感知虚拟电路的神经网络模型,从而实现对等离子体形状参数的独立控制。该方法不仅提高了控制精度和鲁棒性,还为复杂等离子体场景下的实时控制提供了可扩展的解决方案。

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Reliable position and shape control in tokamak plasmas requires accurate real-time regulation of several strongly coupled shape parameters. The control vectors that disentangle these couplings, referred to as \textit{virtual circuits} (VCs), enable independent shape parameter control for a specific Grad--Shafranov (GS) equilibrium. Numerical calculation of VCs is not currently feasible in real time, therefore VCs are usually computed prior to each experiment, using a small number of reference GS equilibria sampled along the desired scenario trajectory, with each VC used to control the plasma within a preset time interval. While effective near the reference equilibrium, this approach can lead to degraded performance as the plasma departs from the reference equilibrium and/or from the desired trajectory, and it complicates the design of robust control strategies for rapidly evolving plasma configurations. In this paper, we construct neural-network-based emulators of plasma shape parameters from which VCs can be derived, to provide the MAST Upgrade (MAST-U) plasma control system with state-aware VCs in real-time. To do this, we develop an extensive library of over a million simulated GS equilibria, covering a substantial portion of the MAST-U operational space. These emulators provide differentiable functions whose gradients can be rapidly computed, enabling the derivation of accurate VCs for real-time shape control. We perform extensive verification of the emulated VCs by testing whether they disentangle the control problem. The neural-network-based approach delivers high accuracy and orthogonality across a diverse range of equilibria. This work establishes the physical validity of emulated VCs as a scalable and general alternative to schedules of precomputed VCs.

2605.14883 2026-05-15 eess.SP cs.HC cs.LG

BCI-Based Assessment of Ocular Response Time Using Dynamic Time Warping Leveraging an RDWT-Driven Deep Neural Framework

Shantanu Sarkar, Sai Shashank Gandavarapu, Jeff Feng, Saurabh Prasad, Reza Khanbabaie, Jose L. Contreras-Vidal

发表机构 * Dept. of ECE, IUCRC BRAIN, Cullen College of Engineering University of Houston, Houston, USA Dept. of Data Science, Cullen College of Engineering University of Houston, Houston, USA Dept. of Industrial Design, IUCRC BRAIN, Gerald D.Hines College of Arch. \& Design University of Houston, Houston, USA Neurotechnology \& BCI Cognixion Inc. Toronto, Ontario, Canada

AI总结 该研究提出了一种基于脑机接口(BCI)的方法,用于评估眼部反应时间,以辅助轻度脑外伤(mTBI)的早期诊断。研究结合了脑电图(EEG)与增强现实(AR)引导的前庭/眼动筛查(VOMS)任务,利用冗余离散小波变换(RDWT)驱动的深度神经网络框架处理EEG信号,并通过动态时间规整(DTW)计算眼部反应时间。实验结果表明,该方法在区分不同受试者的眼动行为方面具有显著效果,尤其在追踪任务中表现出良好的时间差异识别能力,为多模态mTBI评估提供了新的技术途径。

Comments Submitted to IEEE SMC 2026 (under review)

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英文摘要

Mild traumatic brain injury (mTBI) is a prevalent condition that remains difficult to diagnose in its early stages. Oculomotor dysfunction is a well-established marker of mTBI, motivating the development of portable tools that capture both eye-movement behavior and underlying neurophysiology. In this work, we present an initial framework that integrates electroencephalogram (EEG) with augmented-reality (AR)-based Vestibular/Ocular Motor Screening (VOMS) tasks to estimate subject-specific ocular response times. Pre-processed EEG signals, obtained through band-pass filtering and average referencing, are analyzed using a Redundant Discrete Wavelet Transform (RDWT)-driven deep neural framework. The RDWT coefficients are subjected to trainable zero-phase convolutional filtering and reconstructed into the time domain via inverse RDWT, followed by channel-wise temporal and spatial filtering using 2D convolution layers and convolutional-LSTM-based decoding. An ablation study demonstrates that wavelet-domain filtering serves as an effective denoising strategy, improving prediction performance. Sliding-window predictions were validated using Pearson correlation (>= 0.5), and Dynamic Time Warping (DTW) was subsequently used to estimate ocular response times. DTW-derived metrics revealed significant inter-subject differences across all VOM tasks, supported by Mann-Whitney U tests. Cross-correlation analysis further revealed task-dependent temporal behaviors: pursuit tasks exhibited reactive tracking, whereas saccades showed anticipatory responses. Overall, the results highlight pursuit tasks as particularly informative for distinguishing timing differences and demonstrate the potential of RDWT-based EEG features combined with DTW metrics for multimodal mTBI assessment.

2605.14879 2026-05-15 cs.MA cs.GT cs.LG

Temporal Fair Division in Multi-Agent Systems: From Precise Alternation Metrics to Scalable Coordination Proxies

Nikolaos Al. Papadopoulos

发表机构 * University of Macedonia(希腊米科诺斯大学)

AI总结 本文研究多智能体系统中时间维度上的公平分配问题,提出了一种新的度量方法——旋转周期性(RP),以及滑动窗口度量ALT,用于评估多智能体在重复资源竞争中的时间公平性。研究通过引入“完美交替”(PA)作为时间公平的典型解,将时间公平分解为旋转得分(RS)和等待期评估(WPE)两个子指标,显著提升了计算效率。实验表明,RP在保持高区分度的同时,相比ALT具有更高的计算效率,两者结合可为时间公平分配提供有效的诊断工具。

Comments 15 pages, 3 figures, 8 tables. Submitted to ACM Transactions on Economics and Computation, Special Issue on Fair Division

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英文摘要

A plethora real-world environments require agents to compete repeatedly for the same limited resource, calling for a temporal notion of fairness judged across entire interaction histories. This paper advances the theory of temporal fair division by introducing Rotational Periodicity (RP), a family of lightweight metrics, alongside the ALT family of sliding-window measures, within a unified framework for repeated multi-agent resource competition. We formalise the Multi-Agent Battle of the Exes (MBoE) as a repeated fair division instance and establish Perfect Alternation (PA) as its canonical temporally fair solution, drawing connections to proportionality, envy-freeness, and n-periodic round-robin allocation. RP decomposes temporal fairness into two complementary sub-measures: Rotational Score (RS) and Waiting Periods Evaluation (WPE), achieving O(nu+n) time complexity versus the O(nu*n) of ALT, where nu is the episode count and n the agent count. Empirical evaluation across n in {2,3,5,8,10} reveals three findings. First, both RP and ALT expose a coordination failure invisible to traditional metrics: Q-learning agents perform worse than random policies by 10-73% on RP and 7-35% on CALT, while Reward Fairness remains misleadingly high (above 0.92 for n>=3). Second, RP achieves 12-25x computational speedup over ALT, growing with n. Third, the two families are complementary: ALT provides richer discrimination for small populations; RP scales reliably where ALT becomes intractable. Together they form a diagnostic toolkit for temporal fair division.

2605.14866 2026-05-15 cs.SE cs.AI

Towards In-Depth Root Cause Localization for Microservices with Multi-Agent Recursion-of-Thought

Lingzhe Zhang, Tong Jia, Kangjin Wang, Chiming Duan, Minghua He, Rongqian Wang, Xi Peng, Meiling Wang, Gong Zhang, Renhai Chen, Ying Li

发表机构 * Peking University(北京大学) Huawei Theory Lab(华为理论实验室)

AI总结 随着微服务系统因动态交互和运行环境变化而日益复杂,故障频率不断上升,准确的根因定位(RCL)对系统可靠性至关重要。现有基于传统机器学习和深度学习的方法在可解释性和跨部署迁移能力方面存在不足,而基于大语言模型(LLM)的方法虽有所改进,但仍面临上下文爆炸和串行推理结构导致的诊断效率与准确性问题。本文提出RCLAgent,一个基于多智能体递归思维的微服务根因定位框架,通过并行推理分解诊断过程,显著提升了定位精度和推理效率。

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英文摘要

As modern microservice systems grow increasingly complex due to dynamic interactions and evolving runtime environments, they experience failures with rising frequency. Ensuring system reliability therefore critically depends on accurate root cause localization (RCL). While numerous traditional machine learning and deep learning approaches have been explored for this task, they often suffer from limited interpretability and poor transferability across deployments. More recently, large language model (LLM)-based methods have been proposed to address these issues. However, existing LLM-based approaches still face two fundamental limitations: context explosion, which dilutes critical evidence and degrades localization accuracy, and serial reasoning structures, which hinder deep causal exploration and impair inference efficiency. In this paper, we conduct a comprehensive study of both how human SREs perform root cause localization in practice and why existing LLM-based methods fall short. Motivated by these findings, we introduce RCLAgent, an in-depth root cause localization framework for microservice systems that realizes multi-agent recursion-of-thought with parallel reasoning. RCLAgent decomposes the diagnostic process along the trace graph by assigning each span to a Dedicated Agent and organizing agents recursively and in parallel according to the graph topology, with the final diagnosis obtained by synthesizing the Root-Level Diagnosis Report and the Global Evidence Graph. Extensive experiments on multiple public benchmarks demonstrate that RCLAgent consistently outperforms state-of-the-art methods in both localization accuracy and inference efficiency.

2605.14860 2026-05-15 math.OC cs.LG

A Non-Monotone Preconditioned Trust-Region Method for Neural Network Training

Andrea Angino, Bindi Çapriqi, Shega Likaj, Ken Trotti, Rolf Krause

发表机构 * UniDistance Suisse(UniDistance瑞士) King Abdullah University of Science and Technology(卡布斯大学) Università della Svizzera italiana(瑞士意大利大学)

AI总结 本文提出了一种非单调预条件信任区域方法(NAPTS),用于大规模神经网络训练。该方法基于加性预条件信任区域策略(APTS),引入非单调接受准则和非线性加性施瓦茨预条件子,结合并行子域修正与全局粗空间方向,有效提升了训练效率。实验表明,NAPTS在保持精度的同时,将CPU时间减少了30%,并显著降低了被拒绝的迭代步数。

Comments 7 pages, 2 figures,

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英文摘要

Training deep neural networks at scale can benefit from domain decomposition, where the network is split into subdomains trained in parallel and coupled by a global trust-region mechanism. Building on the Additively Preconditioned Trust-Region Strategy (APTS), we propose a non-monotone variant with a nonlinear additive Schwarz preconditioner that combines parallel subdomain corrections with global coarse-space directions. A windowed acceptance criterion allows controlled objective increases, avoiding needless rejection of effective coarse steps. The resulting non-monotone APTS (NAPTS) preserves accuracy while reducing CPU time by 30\% and cutting rejected steps to one third of those in APTS.

2605.14851 2026-05-15 cs.MA cs.AI

IFPV: An Integrated Multi-Agent Framework for Generative Operational Planning and High-Fidelity Plan Verification

Zhigao Huang, Zhengqing Hu, Dong Chen, Shaohan Zhang, Zhao Jin, Bo Zhang, Han Wu, Mingliang Xu

发表机构 * School of Computer and Artificial Intelligence, Zhengzhou University(郑州大学计算机与人工智能学院) Engineering Research Center of Intelligent Swarm Systems, Ministry of Education(教育部智能群体系统工程研究中心) National Supercomputing Center in Zhengzhou(郑州国家超算中心) Henan Research Center for Large Model Technology(河南省大模型技术与新质软件工程研究中心)

AI总结 本文提出了一种集成多智能体框架IFPV,用于生成作战计划并进行高保真度的计划验证。该框架包含两个紧密耦合的模块:多视角分层智能体MPHA用于生成作战行动序列,以及对抗认知仿真引擎ACSE用于高保真度的对抗验证。实验表明,IFPV在任务成功率和操作成本方面优于传统方法,验证模块也显著提升了对候选计划潜在漏洞的识别能力。

Comments Submitted to Neurocomputing

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英文摘要

Operational plan generation and verification are critical for modern complex and rapidly changing battlefield environments, yet traditional generation and verification methods still respectively face the challenges of generation infeasibility and verification insufficiency. To alleviate these limitations, we propose an Integrated Multi-Agent Framework for Generative Operational Planning and High-Fidelity Plan Verification (IFPV). IFPV consists of two tightly coupled modules: Multi-Perspective Hierarchical Agents (MPHA) for generative operational planning and an Adversarial Cognitive Simulation Engine (ACSE) for high-fidelity adversarial plan verification. MPHA decomposes commander intent into executable multi-platform tactical action sequences through the collaboration of Pathfinder, Analyst, and Planner agents. ACSE introduces an opponent equipped with a customized world model, which predicts the future evolution of mission-critical platforms and conducts dynamic counteractions against candidate plans. Simulation experiments in the Asymmetric Combat Tactic Simulator (ACTS) show that IFPV improves mission success by 19.4% and reduces operational cost by 41.7% compared with a single-step large language model (LLM) planning baseline. Compared with a traditional rule-based validator, ACSE increases the average suppression rate by 31.8%, indicating that the proposed verification environment is stricter and more discriminative in revealing the latent vulnerabilities of candidate plans. The code for IFPV can be found at https://github.com/zhigao3ks/IFPV.

2605.14828 2026-05-15 stat.ML cs.LG stat.ME

K-Models: a Flexible and Interpretable Method for Ordinal Clustering with Application to Antigen-Antibody Interaction Profiles

Giulia Patanè, Alessandra Menafoglio, Alexander Krauth, Peter Fechner, Luca Dede', Bianca Maria Colosimo, Federica Nicolussi

发表机构 * MOX, Department of Mathematics, Politecnico di Milano(数学系,米兰理工学院MOX部门) Department of Mechanical Engineering, Politecnico di Milano(机械工程系,米兰理工学院)

AI总结 该研究提出了一种名为K-Models的新型聚类方法,用于处理具有序数关系的函数型数据,旨在在保证聚类性能的同时提升模型的可解释性。该方法通过引入序数约束,估计生成观测函数型数据的随机过程中的关键要素,从而更准确地识别数据的内在结构。研究通过仿真和实际应用(如抗原-抗体相互作用的反射传感器数据)验证了该方法的有效性,展示了其在具有潜在序数结构的数据分析中的优越性和实用性。

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英文摘要

Existing clustering methods for functional data often prioritize partitioning accuracy over interpretability, making it challenging to extract meaningful insights when the data-generating process follows a specific underlying structure and an ordinal relationship among clusters is suspected. This work introduces K-Models, a novel framework that integrates ordinal constraints and estimates key underlying elements of the random process generating the observed functional profiles, improving both interpretability and structure identification. The proposed method is evaluated through simulations and real-world applications. In particular, it is tested on Region of Interest (ROI) curves, which represent reaction profiles from a reflectometric sensor monitoring biomolecular interactions, such as antigen-antibody binding. These curves represent changes in reflected light intensity over time at multiple measurement spots with immobilized antigens during analyte exposure, capturing the binding dynamics of the system. The goal is to identify intrinsic signal patterns solely from the observed dynamics, making this dataset an ideal benchmark for assessing the added interpretability of the proposed approach. By incorporating structural assumptions into the clustering process, K-Models enhances interpretability while maintaining performance comparable to state-of-the-art techniques, providing a valuable tool for analyzing functional data with an underlying ordinal structure.