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2605.05902 2026-05-08 cs.SE

Evaluating Non-English Developer Support in Machine Learning for Software Engineering

评估机器学习软件工程中非英语开发者支持

Jonathan Katzy, Yongcheng Huang, Gopal-Raj Panchu, Maksym Ziemlewski, Paris Loizides, Sander Vermeulen, Arie van Deursen, Maliheh Izadi

AI总结 研究评估非英语代码注释生成及现有评估方法的可靠性,发现非英语环境下生成性能显著下降,自动评估方法无法可靠区分正确与错误注释。

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AI中文摘要

大型语言模型在软件工程中被越来越多地使用,但代码生成及其评估仍以英语为中心,导致对当前工具支持多语言开发的理解存在重大空白。本文研究非英语代码注释生成及现有方法的可靠性,评估了五种代码LLM在五种自然语言中的表现,生成12,500条注释并发布公开标注数据集及26种错误类型分类。研究发现,非英语环境下生成性能大幅下降,语言错误增加15.1倍,伴随不一致生成和语义错误。自动方法无法可靠评估非英语注释,神经度量和LLM-as-judge方法均无法有效捕捉语言和语义错误,显示人类判断仍不可或缺。

英文摘要

Large Language Models are increasingly used in software engineering, but both code generation and its evaluation remain predominantly English-centric. This leaves a major gap in our understanding of how well current tools support multilingual development, where code contains non-English natural language. In this paper, we investigate non-English code comment generation and the reliability of current methods for evaluating such outputs. We evaluate five code LLMs (CodeGemma, CodeLlama, CodeQwen1.5, GraniteCode, and StarCoder2) across five natural languages: Dutch, English, Greek, Polish and Chinese. We further conduct an open-coding study of 12,500 generated comments, from which we derive a publicly released human-annotated dataset and a taxonomy of 26 error types. We use these human annotations, to evaluate the performance of neural metrics, and LLM-as-a-judge pipelines. Our findings show that generative performance deteriorates substantially outside English, with linguistic errors increasing by up to 15.1$\times$, alongside frequent incoherent generations and a rise in semantic errors. More critically, we show that detecting errors in non-English comments underperforms. Across classical overlap-based metrics, off-the-shelf neural metrics, extended neural metrics using newer multilingual, language-specific, and code-specific models, and LLM-as-a-judge pipelines, no automatic approach provides reliable and consistent assessment. Neural metrics fail to distinguish correct comments from incorrect outputs or even random noise, and tend to overestimate quality in non-English settings. LLM-as-a-judge methods achieve the highest agreement with human annotations but fail to reliably capture important language-related and semantic errors. Overall, our results show that evaluation and generation are key barriers for multilingual tooling, and that human judgment remains indispensable.

2605.05901 2026-05-08 cs.CE

Duplicate-Aware Shift-and-Lift Carleman Linearization:Structure, Complexity, and Comparative Evaluation

具有重复意识的移位-提升Carleman线性化:结构、复杂性和比较评估

Takaki Akiba, Youhi Morii

AI总结 本文提出一种移位-提升架构以消除Carleman线性化中因状态维度和截断阶数增加而产生的重复单项式贡献,通过移动中心扩展提高高阶截断的实用性,并通过对比实验验证了该方法在双线性驱动和逻辑交互等基准测试中的收敛性与准确性。

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AI中文摘要

本研究的主要目标是消除Carleman线性化中因状态维度和截断阶数增加而产生的重复单项式贡献。为此,我们采用移位-提升架构,因为它能够暴露重复的指数目标,并在提升运算符组装过程中实现重复意识的系数合并。该架构也使高阶截断成为可能,但该区域会加剧更高阶非线性关系的局部收敛性和闭合敏感性。因此,我们通过移动中心扩展将移位-提升结合在一起,使移位和提升在演变的局部中心周围共同更新,从而提高截断模型沿轨迹的有效性。所得到的工作流程结合了对称减少的单项式基、压缩指数键索引和稀疏三元组合并,以在保留截断仿射动态的同时减少索引分辨率的开销和写路径的不规则性。我们分析了变量增长、预处理复杂性和截断引起的误差机制,并通过固定步长误差、可接受的步长大小和目标精度成本标准与雅可比线性化进行了比较。两个基准(双线性驱动和逻辑交互)显示,两种方法在细化下均能收敛,但所提方法在特定区域具有更高的精度,而非普遍优势。

英文摘要

The primary objective of this study is to remove duplicated monomial contributions that proliferate in Carleman linearization as state dimension and truncation order increase. To do so, we adopt a shift-and-lift architecture, since it exposes repeated exponent targets and allows duplicate-aware coefficient coalescing during lifted-operator assembly. This architecture also makes high-order truncation practical, but that regime intensifies local convergence and closure sensitivity for higher-order nonlinearities. We therefore pair shift-and-lift with a moving-center expansion so that shift and lift are updated jointly around evolving local centers, improving validity of the truncated model along the trajectory. The resulting workflow combines symmetry-reduced monomial bases, packed exponent-key indexing, and sparse triplet coalescing to preserve truncated affine dynamics while reducing index-resolution overhead and write-path irregularity. We analyze variable growth, preprocessing complexity, and truncation-induced error mechanisms, and we compare against Jacobian linearization through fixed-step error, admissible step size, and cost-at-target-accuracy criteria. Two benchmarks (bilinear driver and logistic interaction) show convergence under refinement for both approaches, with regime-dependent accuracy gains for the proposed method rather than universal superiority.

2605.05898 2026-05-08 econ.GN q-fin.EC

Migration-Driven Demographic Changes: effects on local communities in the canton of Fribourg

人口迁移驱动的人口变化:瑞士弗里堡州本地社区的影响

Emma Bacci

AI总结 研究分析了瑞士弗里堡州人口增长对本地社区的影响,采用差分法估计迁移对人口、教育和住房结果的影响,发现迁移对人口结构、教育和住房有持续调整作用。

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AI中文摘要

人口迁移正在重塑欧洲的人口景观,引发关于适应快速人口变化的紧迫问题。本研究分析了瑞士弗里堡州,该州在过去15年中人口增长了30%,主要由国际和国内迁移驱动。随着地方政府面临人口变化在住房、教育和社会服务方面的压力,理解迁移的影响对于基于证据的政策制定至关重要。我们研究了迁移如何重塑112个弗里堡市镇(2010-2021)的本地人口、教育和住房结果。使用De Chaisemartin和D'Haultfoeuille(2024)的跨时期差异-in-差异估计量,该方法可以处理 staggered timing 和累积、非二元处理,我们识别了累计迁移平衡(相对于基线人口)每增加一个百分点的影响。迁移暴露在人口、教育和住房维度上产生适度但持续的调整。两种迁移类型都减少了老年人口比例,而国际流入与更高的出生率相关。国内迁移增加了居民学生人数并改变了强制性和中学阶段的班级,而国际迁移略微降低了高等教育比例。住房调整是渐进的,集中在家庭构成和选定的居住类型上,国际迁移增加了中等规模的家庭,而国内迁移减少了混合用途的居住类型。尽管年度影响较小,但其持续性产生了有意义的累积变化。总体而言,迁移成为对抗人口老龄化的一种反作用力,并产生了服务需求的增量调整,强调了将迁移暴露纳入州和市规划的重要性。

英文摘要

Migration is reshaping demographic landscapes across Europe, raising urgent questions about adapting to rapid population changes. This study examines the canton of Fribourg, Switzerland, which experienced a 30% population increase over the past 15 years, driven by international and internal migration. As local governments face mounting pressures from demographic shifts in housing, education, and social services, understanding the causal effects of migration is essential for evidence-based policymaking. We study how migration reshapes local demographic, educational, and housing outcomes across 112 Fribourg municipalities (2010-2021). Using the intertemporal difference-in-differences estimator of De Chaisemartin and D'Haultfoeuille (2024), which accommodates staggered timing and cumulative, non-binary treatment, we identify the effect of a one-percentage-point increase in cumulative migration balance (relative to baseline population). Migration exposure generates modest but persistent adjustments across demographic, educational, and housing dimensions. Both migration types reduce the share of elderly residents, and international inflows are associated with higher birth counts. Internal migration increases resident students and alters compulsory and secondary-school cohorts, while international migration slightly reduces the tertiary-education share. Housing adjustments are gradual and concentrated in household composition and selected dwelling types, with international migration increasing mid-sized households and internal migration reducing mixed-use dwellings. Though yearly effects are small, their persistence yields meaningful cumulative changes. Overall, migration acts as a counterweight to population aging and generates incremental adjustments in service demand, underscoring the need to incorporate migration exposure into cantonal and municipal planning.

2605.05888 2026-05-08 cs.AR cs.DC

MoE-Hub: Taming Software Complexity for Seamless MoE Overlap with Hardware-Accelerated Communication on Multi-GPU Systems

MoE-Hub:通过硬件加速通信降低软件复杂性以实现多GPU系统中无缝的MoE重叠

Zhuoshan Zhou, Chen Zhang, Shuyi Zhang, Qijun Zhang, Haibo Wang, Zhe Zhou, Zhipeng Tu, Guangyu Sun, Yijia Diao, Zhigang Ji, Jingwen Leng, Guanghui He, Minyi Guo

AI总结 本文提出MoE-Hub,通过硬件软件协同设计解决多GPU系统中MoE动态令牌到专家映射与GPU静态地址通信模型的不匹配问题,实现通信与计算的无缝重叠,提升性能和灵活性。

Comments Accepted to ISCA 2026

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AI中文摘要

混合专家(MoE)架构对于扩展大语言模型至关重要,但其可扩展性严重受限于多GPU系统中GPU间通信瓶颈。尽管重叠通信与计算是一种广受认可的优化方法,但其有效部署仍面临性能和编程性的挑战。本文发现问题的根本原因在于MoE的动态、不规则的令牌到专家映射与现代GPU静态、地址中心化的通信模型之间的基本抽象不匹配,这需要复杂的软件中介阶段来解析地址,限制了性能和软件灵活性。为解决这一问题,我们提出MoE-Hub,一种硬件软件协同设计,引入了目标无关的通信范式。MoE-Hub将数据传输与地址管理解耦,允许生产者在路由后仅使用逻辑目标立即发送数据,而地址分配和数据流协调由GPU枢纽中的轻量级硬件透明处理。通过硬件加速整个通信控制平面,MoE-Hub实现了无缝和透明的重叠。我们的评估显示,MoE-Hub在每层和端到端速度上分别比最先进的系统提高了1.40x-3.08x和1.21x-1.98x。

英文摘要

The Mixture-of-Experts (MoE) architecture is crucial for scaling large language models, but its scalability is severely limited by inter-GPU communication bottlenecks in multi-GPU systems. Although overlapping communication with computation is a widely recognized optimization, its effective deployment still remains challenging, both in terms of performance and programmability. In this work, we identify the root cause as a fundamental abstraction mismatch between MoE's dynamic, irregular token-to-expert mapping and the static, address-centric communication model of modern GPUs, which necessitates a complex software mediation phase to resolve addresses before data transfers, limiting performance and software flexibility. To resolve this, we propose MoE-Hub, a hardware-software co-design that introduces a destination-agnostic communication paradigm. MoE-Hub decouples data transmission from address management, allowing producers to send data immediately after routing using only a logical destination, while address allocation and data-flow orchestration are handled transparently by lightweight hardware in the GPU hub. By hardware-accelerating the entire communication control plane, MoE-Hub enables seamless and transparent overlap. Our evaluation shows that MoE-Hub achieves 1.40x-3.08x per-layer and 1.21x-1.98x end-to-end speedup over state-of-the-art systems.

2605.05887 2026-05-08 cs.CR

ActiveFlowMark: Assessing Tor Anonymity under Active Bandwidth Watermarking

ActiveFlowMark: 评估在主动带宽水印下的Tor匿名性

Zilve Fan, Zijian Zhang, Yangnan Guo, Jiaqi Gao, Zhen Li, Mengyu Wang, Chengxiang Si, Liehuang Zhu

AI总结 本文提出NATA算法,通过可控带宽扰动注入可区分的吞吐模式,无需端点控制或修改Tor浏览器,实现对Tor流量的主动流量相关分析,验证主动带宽扰动作为基础设施级侧信道的有效性。

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AI中文摘要

低延迟匿名网络如Tor仍易受利用加密通信中可观测到的侧信道信息的基础设施级流量分析攻击。我们引入NATA,一种非侵入性的主动流量相关分析算法,通过受控带宽扰动向流量注入可区分的吞吐模式。与被动相关方法不同,NATA不需要端点控制、Tor浏览器修改或数据包负载解密或修改。它可以由控制上游网络网关并观察由攻击者控制的退出中继的攻击者执行。为了在显著的网络变化下识别扰动流量,我们开发了BM-Net(带宽调制网络),一种适应于带宽调制检测的选性状态空间学习框架。鉴于现实世界跨洲Tor路径的高保真地面真相有限,BM-Net采用数据高效的策略,将自监督表示学习与监督任务特定分类分离。它首先通过掩码预训练学习可重用的流量表示,然后利用任务特定的标记数据将这些表示适应到二进制扰动检测和细粒度调制分类。通过实际Tor流量测量,BM-Net在我们评估的设置下实现了99.65%的二进制检测F1分数和97.5%的细粒度调制分类宏F1分数。此外,使用基于tornettools的扩展模拟估计在带宽加权中继选择下的退出观察概率。这些结果表明,在明确的攻击者模型下,主动带宽扰动可以作为基础设施级侧信道用于流量相关分析。

英文摘要

Low-latency anonymity networks such as Tor remain vulnerable to infrastructure-level traffic analysis that exploits side-channel information observable from encrypted communications. We introduce NATA, a non-invasive active traffic-correlation analysis algorithm that injects distinguishable throughput patterns into traffic flows through controlled bandwidth perturbations. Unlike passive correlation methods, NATA does not require endpoint compromise, Tor-browser modification, or packet-payload decryption or modification. It can be carried out by an adversary that controls an upstream network gateway and observes traffic at adversary-controlled exit relays. To identify perturbed flows under substantial network variability, we develop BM-Net (Bandwidth Modulation Network), a selective state-space learning framework adapted for bandwidth-modulation detection. Given the limited availability of high-fidelity ground truth on real-world cross-continental Tor paths, BM-Net adopts a data-efficient learning strategy that separates self-supervised representation learning from supervised task-specific classification. It first learns reusable traffic representations through masked pre-training on serialized traffic traces, and then adapts these representations to binary perturbation detection and fine-grained modulation classification using task-specific labeled data. Through real Tor traffic measurements, BM-Net achieves a 99.65% binary detection F1 score and a 97.5% macro-F1 score for fine-grained modulation classification under our evaluated settings. In addition, tornettools-based scaled simulations are used to estimate exit-observation probability under bandwidth-weighted relay selection. These results suggest that active bandwidth perturbation can serve as an infrastructure-level side channel for traffic correlation under a clearly defined adversary model.

2605.05885 2026-05-08 cond-mat.mtrl-sci

Unraveling the Origin of Ferrimagnetic Signatures in (Fe,Mn,Ga)2O3 Bixbyites: The Role of Structurally-Undetectable Spinel Impurities

解析(Fe,Mn,Ga)2O3 Bixbyite中铁磁特征起源:结构不可检测的尖晶石杂质的作用

Evgeniya Moshkina, Yuriy Knyazev, Ekaterina Smorodina, Oleg Bayukov, Maxim Molokeev, Evgeniy Khramov, Andrey Kartashev, Ruslan Batulin, Mikhail Cherosov, Dmitriy Velikanov, Evgeniy Eremin, Mikhail Rautskii, Dieter Kokh, Mikhail Platunov, Leonard Bezmaternykh

AI总结 研究三种Fe2-xMnxO3:Ga固溶体及无镓参考样品的磁性状态,发现低温磁异常更符合自旋玻璃冻结而非传统反铁磁有序,归因于样品化学纯度和合成技术差异。

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AI中文摘要

立方Fe2-xMnxO3是一种具有广泛应用的材料,包括锂离子电池负极、催化剂、储能介质、湿度传感器和光催化剂。尽管其应用广泛,Fe2-xMnxO3的磁性特性仍存在争议,不同来源报告的磁序类型、相变温度和磁矩数据存在冲突。本研究通过EDX、XRD和XAS分析合成样品的化学组成和晶体结构,结合磁性测量和莫塞纳特谱分析,发现低温磁异常更符合自旋玻璃冻结而非传统长程反铁磁有序。尽管磁性行为变化受组成和合成冷却速率影响,但结果表明这些因素无法解释类似bixbyite型氧化物的显著磁性差异。所观察到的样品中自旋玻璃态可能归因于痕量尖晶石型杂质相,这由磁化率和ESR测量支持。因此,这些差异的主要原因在于样品的化学纯度以及所采用的合成技术。

英文摘要

The cubic Fe2-xMnxO3 is an intriguing material that has recently been investigated for various applications, including lithium-ion battery anodes, catalysts, energy storage media, humidity sensors, and photocatalysts. Despite its wide range of promising applications, the magnetic properties of Fe2-xMnxO3 remain controversial, with different sources reporting conflicting information regarding the type of magnetic ordering, phase transition temperature, and magnetic moment of this compound. This work presents a study of the magnetic state of three Fe2-xMnxO3:Ga solid solutions with varying Mn:Fe:Ga ratios, along with one gallium-free Fe2-xMnxO3 reference sample. We performed a detailed analysis of the actual chemical composition and crystal structure of the synthesized samples using energy-dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS) to evaluate compositional differences. The magnetic states of the three Fe2-xMnxO3:Ga samples and the gallium-free Fe2-xMnxO3 were investigated using magnetometry and Mossbauer spectroscopy. The low-temperature magnetic anomalies were found to be more consistent with spin-glass-like freezing than with conventional long-range antiferromagnetic ordering. Although variations in magnetic behavior were observed and found to depend on composition and the cooling rate during synthesis, our results demonstrate that these factors do not account for the drastically different magnetic properties reported for similar bixbyite-type oxides. Instead, the apparent room-temperature ferrimagnetism observed in one sample is most likely extrinsic and can be attributed to a trace spinel-type impurity phase, as supported by magnetizations and ESR measurements. Thus, the origin of these discrepancies lies primarily in the chemical purity of the samples and, to a significant extent, in the synthesis technique employed.

2605.05884 2026-05-08 eess.SP

From Multi-Port Models to Cascade Structures: Optimization of Active Unilateral Stacked Intelligent Metasurfaces

从多端口模型到级联结构:主动单向堆叠智能超材料的优化

Andrea Abrardo, Giulio Bartoli, Alberto Toccafondi, Marco Di Renzo

AI总结 本文提出一种多端口S参数框架,用于分析和优化具有单向主动互连的堆叠智能超材料,通过非互易两端口网络建模单元胞,实现递归级联结构,提升电磁准确性并降低计算复杂度。

Comments 11 pages, 12 figures, journal

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AI中文摘要

本文开发了一种多端口S参数框架,用于分析和优化具有单向主动互连的堆叠智能超材料(SIMs)。通过将每个单元胞建模为非互易两端口网络,所得到的SIM表现出馈送前向结构,能够递归、级联地表示端到端传输函数,同时保持电磁准确性。基于此模型,我们推导出一种高效的基于梯度的优化算法,其计算复杂度低于传统互易SIM架构。数值结果,通过全波仿真获得,展示了层间间距、主动增益和SIM尺寸在通道对角化和可实现频谱效率之间的权衡。

英文摘要

This paper develops a multi-port S-parameter framework for the analysis and optimization of stacked intelligent metasurfaces (SIMs) with unilateral active interconnections. By modeling each unit cell as a non-reciprocal two-port network, the resulting SIM exhibits a feed-forward structure that enables a recursive, cascade-like representation of the end-to-end transfer function while preserving electromagnetic accuracy. Based on this model, we derive an efficient gradient-based optimization algorithm with reduced computational complexity compared to conventional reciprocal SIM architectures. Numerical results, obtained from full-wave simulations, illustrate the trade-offs among inter-layer spacing, active gain, and SIM size in terms of channel diagonalization and achievable spectral efficiency.

2605.05883 2026-05-08 astro-ph.SR

Modeling of Coronal Mass Ejection Originated from a Sheared Arcade of Realistic Active-Region Scale and Its Propagation in the Heliosphere: Methodology

从现实活动区sheared arcade出发的日冕物质抛射建模及其在日球层中的传播:方法论

Chaowei Jiang, Xueshang Feng, Liping Yang, Huichao Li, Jinhan Guo, Pingbing Zuo, Yi Wang

AI总结 本文提出了一种端到端的日冕物质抛射建模方法,通过三层嵌套磁流体动力学模拟,实现了从太阳表面到1.5 AU的日球层模拟,解决了活动区尺度和真实磁场强度的建模难题。

Comments 20 pages, 11 figures, accepted by ApJ

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AI中文摘要

模拟从活动区(AR)起源到地球传播的日冕物质抛射(CME)仍具挑战性,尤其在追求活动区尺度和真实磁场强度的同时保持计算效率。本文提出了一种端到端的CME建模方法,通过三层嵌套磁流体动力学模拟,共同覆盖从太阳表面到超过1.5 AU的日球层。采用块结构自适应网格细化方案,实现低日冕约700公里的分辨率,允许活动区尺度得以解析,同时保持整个计算域内的总网格数低于10^8。使用半相对论Boris校正与相对论质量密度因子,以处理高达10^3 G的磁场强度而不需极小的时间步长。利用此模型,我们模拟了双极性AR进入日冕、AR核心磁场剪切引发CME的启动及后续发展。我们的模拟捕捉了其爆发前的能量积累,通过磁重联触发,快速加速并传播到1 AU及更远。模拟的CME在合成日冕仪图像中呈现出三部分结构,在日球层中呈现出环形的磁通绳,合成的在轨观测显示了激波形成、密度压缩以及在1 AU处持续的向南B_z分量。整个模拟在中等规模的集群上大约需要一天时间(例如600个处理器),而模拟的CME在到达1 AU时需要三天,如果用于预测则提供两天的提前时间。

英文摘要

Simulating coronal mass ejections (CMEs) from their origin in active regions (ARs) to their propagation to Earth remains challenging, particularly when aiming to resolve AR scales and employ realistic magnetic field strengths without compromising computational efficiency. Here we present a methodology for end-to-end CME modeling that addresses these challenges. Three nested magnetohydrodynamic simulations are coupled to jointly cover the heliosphere from solar surface to beyond $1.5$ au. A block-structured adaptive mesh refinement scheme is employed to achieve $\sim 700$ km resolution in the low corona, allowing AR scales to be resolved while maintaining the total grid count below $10^8$ across the entire computational domain. A semi-relativistic Boris correction combined with a relativistic mass-density factor is used to handle magnetic field strengths up to $10^3$ G without prohibitively small time steps. Using this model, we simulate the emergence of a bipolar AR into the corona, the initiation of a CME by shearing of the AR core field and the subsequent evolution. Our simulation captures its pre-eruption energy buildup, triggering by magnetic reconnection, rapid acceleration, and propagation to 1 au and beyond. The simulated CME exhibits a three-part structure in synthetic coronagraph images and a torus-shaped flux rope in the heliosphere, with synthetic in-situ observations showing shock formation, density compression, and a prolonged southward $B_z$ component at 1 au. The entire simulation requires about one day on a moderately sized cluster (e.g., $600$ processors), while the simulated CME takes three days to arrive at $1$ au, offering a lead time of two days if used for forecasting.

2605.05881 2026-05-08 quant-ph

Surface-Code Thresholds and Qubit Footprints in Shuttling-Based Spin-Qubit Railways

表面码阈值与基于穿梭的自旋量子比特轨道的量子比特足迹

Arun John Moncy, Reza Dastbasteh, Josu Etxezarreta Martinez, Ryo Nagai, Pedro M. Crespo, Normann Mertig, Charles Smith, Ruben M. Otxoa

AI总结 本文提出了一种容错的映射方法,将旋转的表面码映射到2×N硅自旋量子比特轨道架构上,利用电子穿梭解决布线扇出瓶颈。通过电路级噪声建模评估了不同噪声偏置下的阈值性能,证明了使用穿梭检查量子比特而非数据量子比特能显著提高系统阈值。

Comments 14 pages, 12 figures

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AI中文摘要

我们提出了一种容错的映射方法,将旋转的表面码映射到一个2×N硅自旋量子比特轨道架构上,利用电子穿梭来解决布线扇出瓶颈。通过电路级噪声建模,我们评估了在不同噪声偏置下的阈值性能。我们证明,使用穿梭检查量子比特而不是数据量子比特从根本上提高了系统的阈值。关键的是,在针对自旋量子比特穿梭的噪声模型偏向退相干的情况下,非CSS的XZZX表面码优于标准的CSS变体。通过将拓扑码适应这种特定的内在偏置,我们表明,使用距离为7的代码,需要物理错误率为p=10^{-3}时,可以实现Megaquop足迹,这为早期容错量子处理器的显著硬件减少提供了一条路径。

英文摘要

We present a fault-tolerant mapping of rotated surface codes onto a $2\times N$ silicon spin-qubit railway architecture, utilizing electron shuttling to resolve the wiring fan-out bottleneck. Employing circuit-level noise modeling, we evaluate threshold performances across various noise biases. We demonstrate that shuttling check qubits instead of data qubits fundamentally improves system thresholds. Crucially, under a noise model biased towards dephasing for spin-qubit shuttling, the non-CSS XZZX surface code outperforms standard CSS variants. By tailoring the topological code to this specific inherent bias, we show that the Megaquop footprint is achievable with a distance 7 code requiring a $p = 10^{-3}$ physical error rate, highlighting a pathway for substantial hardware reductions in early fault-tolerant quantum processors.

2605.05879 2026-05-08 cond-mat.mtrl-sci

Fermi energy Weyl nodes in $\mathbf{AM}$Te$_4$ ($\mathbf{A}$=Ta, Nb, $\mathbf{M}$=Ir, Rh)

AMTe₄中的费米能韦伊尔节点

Shivam Parasar, Jeroen van den Brink, Rajyavardhan Ray

AI总结 研究通过全面扫描近费米能的子带,揭示了AMTe₄中韦伊尔节点的分布变化,预测其对材料性质有显著影响,并阐明了量子振荡和磁电阻现象的理论与实验联系。

Comments 24 pages , 5 figures, supplementary information

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AI中文摘要

量子振荡和磁电阻在Weyl半金属AMTe₄(A= Nb,Ta,M= Rh, Ir)中的关键方面仍存在开放性问题,阻碍了其拓扑电子结构与实际应用之间的联系。通过通用搜索程序,我们对所有接近费米能的子带进行了全面扫描,发现这大幅改变了这些化合物的WP景观。特别是,我们预测这些化合物中存在几meV内费米能的韦伊尔节点,显著影响其性质。值得注意的是,大多数考虑的化合物宿主多种类型的韦伊尔点,包括NbRhTe₄,其宿主I、II和III类型的韦伊尔点。对结构和计算参数/模型保真度的比较分析不仅提供了这些化合物复杂电子结构的详细映射,还澄清了该家族中量子振荡和磁电阻观测,弥合了理论与实验之间的差距,并提供了一个精确调节韦伊尔点的框架。

英文摘要

Key aspects of the quantum oscillations and magnetoresistance in Weyl semimetals $AM$Te$_4$ ($A$=Nb,Ta, $M$=Rh, Ir) persist as open questions, obscuring the link between their topological electronic structure and practical implementations. Employing a generalised search procedure, we carry out a comprehensive scan of WPs accounting for all the subbands close to the Fermi energy, and show that this dramatically alters the WP landscape in these compounds. In particular, we predict these compounds to feature WPs within a few meV of the Fermi energy which significantly influence their properties. Remarkably, most of the considered compounds host WPs of more than one type, including NbRhTe$_4$ which hosts type-I, II and III Weyl points. Our comparative analysis of structure and fidelity of computational parameters/models not only provides a detailed mapping of the complex electronic structure in these compounds, but also clarifies quantum oscillations and magnetoresistance observations in this family, bridging the gap between theory and experiments and offering a framework for precise tunability of WPs.

2605.05877 2026-05-08 cs.DS math.PR

Discrete Optimal Transport: Rapid Convergence of Simulated Annealing Algorithms

离散最优传输:退火算法的快速收敛性

Yuchen He, Tianhui Jiang, Sihan Wang, Chihao Zhang

AI总结 本文提出离散最优传输框架,分析有限状态空间上的退火算法收敛性,通过定义离散Wasserstein-2距离和离散作用,证明退火算法的KL散度可由离散作用控制,并应用于Ising模型和Potts模型,获得多项式上界。

Comments 67 pages, 1 figure

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AI中文摘要

本文提出离散最优传输框架,用于分析有限状态空间上的退火算法。基于Maas(J. Funct. Anal., 2011)引入的离散Wasserstein度量,我们定义了广义的离散Wasserstein-2距离及相关路径上的离散作用概念。利用这些工具,我们建立了退火算法的非渐近收敛性保证:退火算法输出与目标分布之间的KL散度由退火路径的离散作用控制。这可以视为连续空间中退火Langevin动力学作用基于分析的离散对应物。作为应用,我们分析了统计物理中两个基本模型的退火算法。对于均场Ising模型,我们证明退火单站点Glauber动力学在任何逆温度β≥0的情况下,可在O(n⁵β²/ε)步内达到KL散度误差ε。对于均场q态Potts模型,我们证明退火(q-1)块Glauber动力学在β≥β_s=q/2的范围内(即无序相完全失去稳定性时),可在poly(n, β, 1/ε)步内达到误差ε。关键的技术贡献是通过利用模型的对称性,将分析减少到低维投影链,从而获得离散作用的多项式上界。

英文摘要

We develop a discrete optimal transport framework for analyzing simulated annealing algorithms on finite state spaces. Building on the discrete Wasserstein metric introduced by Maas (J. Funct. Anal., 2011), we define a generalized discrete Wasserstein-2 distance and the associated notion of \emph{discrete action} for paths of probability measures on graphs. Using these tools, we establish non-asymptotic convergence guarantees for simulated annealing: the KL divergence between the algorithm's output and the target distribution is controlled by the discrete action of the annealing path. This can be viewed as the discrete counterpart of the action-based analysis of annealed Langevin dynamics in continuous spaces by Guo, Tao, and Chen (ICLR 2025). As applications, we analyze simulated annealing for two fundamental models in statistical physics. For the \emph{mean-field Ising model}, we show that annealed single-site Glauber dynamics achieves $\varepsilon$ error in KL divergence in $O(n^5β^2/\varepsilon)$ steps at \emph{any} inverse temperature $β\ge 0$. For the \emph{mean-field $q$-state Potts model}, we show that annealed $(q-1)$-block Glauber dynamics achieves $\varepsilon$ error in $\mathrm{poly}(n, β, 1/\varepsilon)$ steps for all $β\ge β_{\mathsf{s}}=q/2$, the regime where the disordered phase has completely lost stability. In both cases, the key technical contribution is a polynomial upper bound on the discrete action, obtained by exploiting the symmetry of the model to reduce the analysis to a low-dimensional projected chain.

2605.05874 2026-05-08 physics.flu-dyn

Comparative Numerical Study of Film Cooling Strategies for Thermal Protection of a Kerosene-Fueled Oblique Detonation Combustor

对比研究不同膜冷却策略用于kerosene燃料斜爆燃燃烧室的热防护

Jianghong Li, Songbai Yao, Wenwu Zhang

AI总结 研究通过数值模拟比较了三种膜冷却策略对斜爆燃燃烧室热防护的影响,发现燃料基冷却能更有效地维持爆燃结构,而雾化冷却在较低质量比下提供最佳热防护与推进性能。

Comments 14 pages, 13 figures

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AI中文摘要

斜爆燃发动机在高超音速条件下面临热防护的关键挑战,由于斜爆燃波带来的极端热量释放和紧凑燃烧室几何结构。本研究通过飞行马赫数为10和海拔15公里的数值模拟,探讨了kerosene-空气斜爆燃燃烧室中三种主动冷却策略的有效性:空气膜冷却、气体-石蜡膜冷却和液态石蜡雾化冷却。结果表明,所有冷却策略均能维持稳定的斜爆燃传播并保持典型的波系结构。空气冷却在起始区域和三重点附近产生更强的扰动,导致下游波相互作用增强和推进惩罚增加。相比之下,基于燃料的冷却引起扰动更温和,能更好地保持全球爆燃结构。所有冷却方法显著降低了近壁热负荷,但其冷却特性差异显著。气体-石蜡膜冷却表现出与离散冷却孔排列相关的空间周期性近壁热响应,而液态石蜡雾化冷却由于增强的两相混合和相变吸热产生更平滑的近壁温度分布。在研究策略中,雾化冷却在冷却剂质量比为1%-3%时提供最佳的热防护与推进性能平衡,而气体-石蜡膜冷却在更高注入水平下因改进的壁面覆盖连续性更具优势。本研究结果展示了基于燃料的膜冷却在高超音速斜爆燃燃烧室热管理中的可行性和潜力。

英文摘要

Thermal protection remains a critical challenge for oblique detonation engines (ODEs) operating under hypersonic conditions due to the extreme heat release and compact combustor geometry associated with oblique detonation waves (ODWs). In the present study, the effectiveness of film cooling for a kerosene-air ODE combustor is numerically investigated under a flight Mach number of 10 and an altitude of 15 km. Three active cooling strategies are considered, including air film cooling, gaseous-kerosene film cooling, and liquid-kerosene mist cooling. The results show that all cooling strategies preserve stable oblique-detonation propagation and maintain the canonical wave-system structure within the investigated operating range. Air cooling produces stronger disturbances near the initiation region and triple point, resulting in enhanced downstream wave interactions and larger propulsion penalties. In contrast, fuel-based cooling induces milder disturbances and better preserves the global detonation structure. All cooling methods substantially reduce the near-wall thermal load, although their cooling characteristics differ significantly. Gaseous-kerosene film cooling exhibits a spatially periodic near-wall thermal response associated with the discrete cooling hole arrangement, while liquid-kerosene mist cooling produces a smoother near-wall temperature distribution due to enhanced two-phase mixing and phase-change heat absorption. Among the investigated strategies, mist cooling provides the best overall balance between thermal protection and propulsion performance at coolant mass ratios of 1%-3%, whereas gaseous-kerosene film cooling becomes advantageous at higher injection levels due to improved wall coverage continuity. The present results demonstrate the feasibility and potential of fuel-based film cooling for thermal management in hypersonic ODE combustors.

2605.05872 2026-05-08 physics.atm-clus

Locally-Induced Stark Shifts of Collective Excitonic Modes in Polyradical Aggregates

聚合物自由基团簇中集体激发子态的局域史特克位移

Amandeep Sagwal, Rodrigo Cezar de Campos Ferreira, Petr Kahan, Maximilian Rödel, Jindřich Nejedlý, Jiří Doležal, Martin Švec

AI总结 研究通过局域电场调控分子团簇中暗态激发子态的挑战,揭示了电场对激发子态谱的影响及暗态发射峰变窄和亮态行为发散的现象。

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AI中文摘要

在分子团簇中主动控制暗态长寿命激发子态使用局部电场是推进纳米尺度光电电子学和量子器件工程的关键挑战。本实验研究了由自由基染料组成的团簇中的集体激发子态。利用尖端增强荧光光谱(TEPL)提供的强光学增强,观察到由于激发子耦合而出现的亮和暗激发子模,并在纳米腔隙中局部施加电场时诱导其光谱变化。揭示了比例缩放的史特克位移以及暗态发射峰变窄和亮态在纳米腔上方不对称测量位置上行为发散的现象。所观察到的复杂行为在场的影响、分子排列、纳米腔耦合、暗模式寿命和电荷不均匀性方面进行了讨论。对外部参数的敏感性展示了对自由基激发子团簇的有效控制手段。

英文摘要

Active control of dark long-lived excitonic states in molecular aggregates using local electric fields is a pivotal challenge for advancing nanoscale optoelectronics and quantum device engineering. This experimental study investigates the collective excitonic states in aggregates composed of radical chromophores. With the strong optical enhancement provided by tip-enhanced photoluminescence (TEPL) spectroscopy, bright and dark excitonic modes are observed emerging due to interexciton coupling and induce changes in their spectra with the electric field locally applied within the nanocavity gap. Proportionally scaling Stark shifts are revealed as well as the emission peak sharpening of the dark states and a divergent behavior of the bright states in asymmetric measurement positions of the nanocavity above the aggregates. The observed complex behavior is discussed in terms of influence of the field, molecule arrangement, nanocavity coupling, dark mode lifetimes and electrostatic charge inhomogeneities in the clusters. This sensitivity to the external parameters demonstrates an effective means of control over radical excitonic aggregates.

2605.05869 2026-05-08 math.AP

Consistency analysis for combined homogenization and shallow water limit of water waves

水波联合均质化与浅水极限的一致性分析

Antoine Gloria, David Lee

AI总结 本文研究浅水模型在均质化框架下的一致性问题,放宽了周期地形条件,针对一般地形提出最小假设。

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AI中文摘要

我们考虑一个在均质化框架下的浅水模型。对于周期地形,Craig、Lannes和Sulem在某些非共振条件下建立了一致性结果。在本文中,我们显著放松了周期性条件,并在最小假设下处理一般地形。

英文摘要

We consider a shallow water model in a homogenization framework. For periodic topographies, Craig, Lannes and Sulem have established a consistency result under some non-resonance conditions. In the present contribution, we significantly relax the periodicity condition and treat general topographies under minimal assumptions.

2605.05868 2026-05-08 cs.CR

SkillScope: Toward Fine-Grained Least-Privilege Enforcement for Agent Skills

SkillScope:迈向细粒度最小特权执行的代理技能

Jiangrong Wu, Yuhong Nan, Yixi Lin, Huaijin Wang, Yuming Xiao, Shuai Wang, Zibin Zheng

AI总结 本文提出SkillScope框架,通过图分析方法实现细粒度最小特权执行,检测技能超特权行为,实验表明其在检测和约束超特权方面效果显著。

Comments 19 pages, 7 figures

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AI中文摘要

Agent Skills已成为扩展LLM代理的实用方法,通过将元数据、自然语言指令和可执行资源打包成可重用能力包。然而,快速增长的Skill生态系统引入了新的合规风险:技能可能执行高影响操作,超出用户当前任务的最小必要范围,从而违反最小特权原则。现有技能检测方法无法解决此问题,因为该问题本质上是任务条件性的:同一操作在一种用户提示下可能是必要的,但在另一种提示下可能过度授权。本文提出SkillScope框架,采用基于图的分析方法,将指令级过程和代码级操作建模为细粒度动作节点。它提取潜在过度授权候选者,在图实例化用户任务下通过回放分析验证,并通过控制流特权约束限制验证的过度授权动作。通过有效性实验和大规模现实世界测量评估SkillScope。SkillScope在技能过度授权检测上达到94.53%的F1值。在现实环境中,SkillScope验证了7,039个存在过度授权行为的技能,表明当前Skill生态系统中最小特权违规普遍存在。在特权约束评估中,SkillScope将触发的过度授权动作-任务实例减少了88.56%,同时保持了合法任务的完成。

英文摘要

Agent Skills have become a practical way to extend LLM agents by packaging metadata, natural-language instructions, and executable resources into reusable capability bundles. However, this growing Skill ecosystem introduces a new compliance risk: a Skill may perform high-impact actions that exceed the minimum necessary scope of the user's current task, thereby violating least-privilege. Existing skill detection approaches are insufficient for this problem because it is inherently task-conditioned: the same action may be necessary under one user prompt but over-privileged under another. In this paper, we present SkillScope, a framework for fine-grained least-privilege enforcement in Agent Skills. SkillScope adopts a graph-based analysis approach that models instruction-level procedures and code-level operations as fine-grained action nodes. It extracts potential over-privilege candidates, validates them under graph-instantiated user tasks through replay-based analysis, and constrains validated over-privileged actions via control-flow privilege constraining. We evaluate SkillScope through effectiveness experiments and large-scale real-world measurement. SkillScope achieves 94.53% F1 for skill over-privilege detection. In the wild, SkillScope validates 7,039 Skills with over-privileged behaviors, showing that least-privilege violations are prevalent in current Skill ecosystems. In the privilege-constraining evaluation, SkillScope reduces triggered over-privileged action-in-task instances by 88.56% while preserving legitimate task completion.

2605.05867 2026-05-08 cs.SE

On Fixing Insecure AI-Generated Code through Model Fine-Tuning and Prompting Strategies

通过模型微调和提示策略修复不安全的AI生成代码

Ali Soltanian Fard Jahromi, Amjed Tahir, Peng Liang, Foutse Khomh

AI总结 本文系统研究了通过模型微调和提示策略增强AI生成代码安全性的方法,分析了不同策略和模型对安全性的提升效果,发现安全改进高度依赖策略和模型,且修复某些漏洞可能引入新漏洞。

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AI中文摘要

AI生成代码的安全性仍是其广泛应用的主要障碍。尽管代码生成模型在功能基准上表现优异,但其输出常包含错误和安全漏洞,影响可信度。本文系统研究了通过微调和提示策略增强代码安全性的方法,评估了不同策略和模型在多种编程语言中的安全提升效果。此外,我们分析了识别出的CWE严重性、共现情况以及修复的意外后果(即修复某些漏洞是否在代码其他部分引入新漏洞)。研究结果表明,安全改进高度依赖策略和模型,尽管某些方法可减少特定漏洞类别,但常导致新漏洞产生。此外,没有策略能一致消除所有模型和场景中的漏洞,凸显了缺乏统一有效“无漏洞”解决方案的现状。

英文摘要

The security of AI-generated code remains a major obstacle to its widespread adoption. Although code generation models achieve strong performance on functional benchmarks, their outputs frequently contain bugs and security weaknesses that undermine their trustworthiness. Prior work has explored a range of approaches to mitigate security issues in AI-generated code, e.g., using static analysis-guided generation and prompt engineering. However, their effectiveness varies widely across models and settings. This paper presents a systematic investigation of strategies for hardening model-generated code against a list of Common Weakness Enumeration (CWE). We assess the extent to which these strategies improve security across models and programming languages, using fine-tuning and prompting approaches for model output refinement. Beyond the prevalence of security weaknesses, we analyse the severity of identified CWEs, their co-occurrence, and the unintended consequences of remediation (i.e., whether fixing certain weaknesses introduces new weaknesses elsewhere in the same code). Our results show that security improvements are highly strategy- and model-dependent. Although some approaches reduce specific classes of weaknesses, they often introduce new weaknesses as side effects of the fixes. Moreover, no strategy consistently eliminates weaknesses across all models and scenarios, highlighting the absence of a universally effective "bulletproof" solution for secure AI-generated code.

2605.05864 2026-05-08 math.PR math.FA

Classification and Metrization of Classes of Smooth measures

光滑测度类的分类与度量化

Takumu Ooi, Kaneharu Tsuchida, Toshihiro Uemura

AI总结 本文从稠密性和局部性角度对光滑测度类进行分类,并探讨其关系,特别是Kato类与有限能量积分的Radon测度关系,引入Miyadera度量并获得Revuz对应关系的连续性。

Comments 36 pages

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AI中文摘要

我们从稠密性和局部性角度对光滑测度类进行分类,并考虑其关系,特别是Kato类与有限能量积分的Radon测度之间的关系。我们还介绍了在Dynkin类上定义的Miyadera度量,并获得了Revuz对应关系的连续性。

英文摘要

We classify the several classes of the set of smooth measures from the perspective of the denseness and the locality, and consider their relationships, in particular, that of the Kato class and Radon measures of finite energy integrals. We also introduce the Miyadera metric on the Dynkin class, and obtain the continuity of the Revuz correspondence.

2605.05860 2026-05-08 math.OC

A closer target setting approach to boundary problems with the Russell graph measure

一种更接近目标设置方法的边界问题研究:Russell图度量

Atsushi Hori, Kazuyuki Sekitani

AI总结 本文提出一种改进的Russell图度量模型,通过引入生产权衡,解决边界问题并增强效率度量的性质,通过实证数据验证其有效性。

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AI中文摘要

Russell图度量(RGM)是DEA模型的一种标准方法,但其效率度量在非负正交体边界处未被良好定义或具有不可接受的属性,这被称为边界问题。现有研究虽已对此进行探讨,但其模型可能无法识别有效目标或无法满足效率度量的一些理想性质。本文将更接近目标设置方法引入RGM模型中,通过生产权衡来克服这些问题。我们证明所提模型的效率度量解决了边界问题,并比现有模型具有更强的性质。我们还证明所提模型的效率分数可通过求解一系列线性规划问题来计算。我们使用现实世界数据集进行数值实验,以说明我们模型提供的目标与现有模型相比更加现实,这也表明了我们模型在应用中的有效性。

英文摘要

A Russell graph measure (RGM) is one of the standard DEA models, but its efficiency measure is not well-defined--or has unacceptable properties--at the boundary of the nonnegative orthant. This is known as a boundary problem. Existing studies have tackled this issue; however, their models may fail to identify an efficient target or fail to satisfy some desirable properties of efficiency measures. In this paper, we incorporate a closer target setting approach into the RGM model with production trade-offs to overcome such issues. We demonstrate that the efficiency measure of the proposed model overcomes the boundary problem and has stronger properties than existing models. We also demonstrate that the efficiency scores of the proposed model can be computed by solving a series of LPs. We conduct a numerical experiment with a real-world dataset to illustrate how targets provided by our model are realistic compared with the existing model, which also suggests the validity of our model in applications.

2605.05859 2026-05-08 stat.ME

Estimation of treatment effects in presence of differential use of post-randomization concomitant medication with time-to-event outcomes

在存在随机化后伴随药物不均使用的情况下治疗效果的估计

Helene C. W. Rytgaard, Edwin Fong, Jens M. Tarp, Thomas A. Gerds, Mark J. van der Laan, Henrik Ravn

AI总结 本文提出在心血管结局试验中,针对2型糖尿病患者,考虑随机化后伴随药物使用对治疗效果估计的影响,采用因果框架中的估计量来隔离研究治疗的具体影响,通过TMLE方法进行灵活调整。

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AI中文摘要

在安慰剂对照随机试验中,随机化后安慰剂组使用伴随药物的比例可能高于治疗组,这会稀释随机化药物在意向治疗分析中估计的全部益处。我们关注2型糖尿病患者的心血管结局试验,其中安慰剂组更可能添加具有已证实心血管保护作用的其他降糖药物。作为意向治疗分析的补充,我们提出了一类在因果框架下的估计量,旨在隔离研究治疗的具体影响,同时平衡各干预组对额外药物的暴露。我们倡导使用特定的随机干预来实现这种平衡,同时最小化因某些治疗组合或特征在数据中不充分表示而产生的正性违反。我们采用目标最小损失基于估计(TMLE)来优化我们的估计量估计过程,同时允许对随访访问的随时间变化的协变量进行灵活调整。最后,我们通过模拟研究和LEADER心血管结局试验中的真实世界例子,展示了方法的应用。

英文摘要

In placebo-controlled randomized trials, the post-randomization use of concomitant medications may be higher in the placebo arm than in the treatment arm. This may dilute the full benefits of the randomized drug as estimated by the intention-to-treat analysis. We focus on cardiovascular outcomes trials in type-2 diabetes patients of glucose-lowering treatments where patients in the placebo arm are more likely to add other glucose-lowering agents with established cardio-protective properties. As a supplement to the intention-to-treat analysis, we propose a class of estimands within a causal framework that isolates the specific impact of the treatment being studied from that of concomitant treatment use. These estimands are defined under time-dependent treatment interventions to balance exposure to additional medications across intervention arms. We advocate for specific stochastic interventions to achieve this balance while minimizing positivity violations, which arise when certain treatment combinations or characteristics are not sufficiently represented in the data. We employ targeted minimum loss-based estimation (TMLE) to optimize the estimation procedure for our estimands while allowing for flexible adjustments for time-dependent covariates from follow-up visits. Finally, we demonstrate the application of the methods through a simulation study and a real-world example from the LEADER cardiovascular outcomes trial, which assessed cardiovascular risk for liraglutide versus placebo.

2605.05858 2026-05-08 cond-mat.mtrl-sci

A Comparative Study of Projected and Unprojected Schemes for Micromagnetic Simulations

微磁模拟中投影与非投影方案的比较研究

Changjian Xie

AI总结 本文比较了微磁模拟中两种时间一阶半隐式方法:隐式Gauss-Seidel方法和半隐式BDF方法,分析了投影步骤对磁化强度恒定约束的影响,发现BDF方法在不同耗散系数下均能稳定模拟磁畴壁运动。

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AI中文摘要

在微磁模拟中,磁化强度的恒定性可通过连续性方程推导得出。由于连续性方程中磁化强度的时间演化方向垂直于由磁化方向和有效场确定的平面,将模型两边与磁化方向取内积可得磁化强度幅值演化率为零,从而保持恒定。从这一角度看,方程本身可维持磁化强度幅值的约束。我们对连续性方程进行了离散化,并比较了两种时间一阶半隐式策略:隐式Gauss-Seidel方法和半隐式BDF方法。我们考虑了这两种方案带与不带投影步骤的比较。微磁模拟结果表明,当耗散系数较大时,不带投影步骤的隐式Gauss-Seidel方法在达到的稳态和磁畴壁运动上与带投影步骤的方法有显著差异。当选择适当的耗散系数时,两种方法的差异缩小,稳态和磁畴壁运动均可模拟。对于另一种方法BDF1,无论耗散系数是大还是小,带与不带投影步骤的结果都相当一致,且能有效模拟磁畴壁运动。

英文摘要

In micromagnetic simulations, the constant magnitude of the magnetization can be derived from the continuity equation. Since the time evolution of the magnetization in the continuity equation is perpendicular to the plane determined by the magnetization and the effective field, taking the inner product of both sides of the model with the magnetization shows that the evolution rate of the magnitude of the magnetization is zero, thus keeping the magnitude constant. From this perspective, the equation itself can maintain the constraint of constant magnetization magnitude. We discretized the continuity equation and compared two first-order semi-implicit strategies in time: one is the implicit Gauss-Seidel method, and the other is the semi-implicit Backward Differentiation Formula (BDF) method. We considered the comparison between these two schemes with and without the projection step. The results of micromagnetic simulations show that when the dissipation coefficient is large, the implicit Gauss-Seidel method without the projection step has significant differences from the method with the projection step in both the achieved steady state and domain wall motion. When an appropriate dissipation coefficient is selected, the difference between the two narrows, and both the steady state and domain wall motion can be simulated. For the other method, BDF1, whether the dissipation coefficient is large or small, the results with and without the projection step are quite consistent, and it can effectively simulate the domain wall motion.

2605.05853 2026-05-08 eess.SY cs.SY

Investigation of Wound Field Synchronous Machines using Soft Magnetic Composites for Automotive Applications

用软磁复合材料研究 wound field 同步电机在汽车应用中的可行性

Andreas Carlsson, Christian Sandström, Viktor Josefsson, Lisa Kjellén, Taha El Hajji, Marcus Lenberg

AI总结 本文研究了软磁复合材料在 wound field 同步电机定子中的应用,通过优化材料和叠片厚度,提高了扭矩和效率,并在全电动驱动单元中实现了89.7%的效率,比传统永磁同步电机提高了1.4个百分点,同时消除了稀土材料,降低了成本,具有环保优势。

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AI中文摘要

本文研究了软磁复合材料(SMCs)在 wound field 同步电机定子中的应用,尽管SMCs传统上用于轴向磁通拓扑结构,但本文探讨了其在径向磁通电动机(EESMs)中的应用。评估了多种SMC材料和叠片厚度,最优配置结合了定子中的SMC材料和转子中的0.35 mm NO35叠片钢。这种组合相比传统设计提高了扭矩和效率。当集成到全电动驱动单元(EDU)中时,该电机在WLTP驱动循环中实现了89.7%的效率,比基于永磁同步电机的EDU提高了1.4个百分点。所提出的解决方案消除了稀土材料,通过更厚的叠片降低了成本,并通过SMC的使用提供了环保效益。这种新的材料组合,此前未在径向EESMs中探索,为经济、高效率、无稀土的汽车牵引电机提供了新的方向。

英文摘要

This paper investigates the application of soft magnetic composites (SMCs) in the stators of wound field synchronous machines for automotive traction. While SMCs are traditionally employed in axial flux topologies, this study examines their use in radial-flux electrically excited synchronous machines (EESMs). Multiple SMC materials and lamination thicknesses are evaluated, with the optimal configuration combining a SMC material in the stator and 0.35 mm NO35 laminated steel in the rotor. This combination delivers improved torque and efficiency compared to conventional designs. When integrated into a full electric drive unit (EDU), this motor achieves 89.7% efficiency over the WLTP drive cycle, representing a 1.4 percentage point improvement over a reference permanent magnet synchronous machine-based EDU. The proposed solution eliminates rare-earth materials, reduces cost through thicker laminations, and offers environmental benefits through SMC utilization. This novel material combination, previously unexplored for radial EESMs, presents a promising direction for affordable, high-efficiency, rare-earth-free automotive traction machines.

2605.05852 2026-05-08 cs.NI cs.SY eess.SY

A Disaster-Aware Integrated TN-NTN System-Level Simulator for Resilient 6G Wireless Networks

面向灾害的集成TN-NTN系统级模拟器用于 resilient 6G 无线网络

Donglin Wang, Anjie Qiu, Qiuheng Zhou, Hans D. Schotten

AI总结 本文提出一个轻量级系统级模拟器,用于评估集成TN-NTN无线网络在部分故障灾害模型下的故障后回退行为,研究极端事件中网络韧性与交通管理。

Comments 6 pages, 4 figures, IEEE PIMRC

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AI中文摘要

非地面网络(NTN)已被3GPP标准化为未来6G系统的关键组成部分,以增强覆盖和韧性。特别是低地球轨道卫星、高空平台站和无人机等NTN技术,预计在极端事件中支持地面网络(TN)。本文提出一个轻量级系统级模拟器,用于评估集成TN-NTN无线网络在部分故障灾害模型下的故障后回退行为。该模拟器遵循3GPP Rel-17/18建模原则,支持概率性地面第五代节点B(gNB)故障和服务迁移至NTN。该模拟器支持在不同用户负载、灾害严重程度和NTN配置级别下,对吞吐量、包接收率(PRR)和延迟进行比较分析。结果展示了地面操作的预期容量-延迟权衡,非地面服务的可靠性和稳定性,以及混合TN-NTN操作的平衡韧性行为。所提出的框架为研究未来集成6G移动系统的无线网络韧性与交通管理提供了可操作的工具。

英文摘要

Non-terrestrial networks (NTN) have been standardized by the 3rd generation partnership project (3GPP) as a key component of future 6G systems to enhance coverage and resilience. In particular, NTN technologies such as low-earth orbit (LEO) satellites, high-altitude platform stations (HAPS), and unmanned aerial vehicles (UAVs) are expected to support terrestrial networks (TN) during extreme events and disasters. In this paper, we present a lightweight system-level simulator for evaluating post-failure fallback behavior in integrated TN-NTN wireless networks under a partial-failure disaster model. The simulator follows 3GPP Rel-17/18 modeling principles, supports probabilistic terrestrial next-generation node B (gNB) failures, and service migration to NTN. The simulator supports comparative analysis of throughput, packet reception ratio (PRR), and latency under different user loads, disaster severities, and NTN provisioning levels. Results show the expected capacity-delay tradeoff of terrestrial operation, the reliability and stability of non-terrestrial service, and the balanced resilience behavior of hybrid TN-NTN operation. The proposed framework provides a tractable tool for studying wireless network resilience and traffic management in future integrated 6G mobile systems.

2605.05849 2026-05-08 math.RA

Spaces of matrices with few eigenvalues (II)

具有少量特征值的矩阵空间(二)

Clément de Seguins Pazzis

AI总结 本文研究特征为2的域中,矩阵空间的最大维度问题,扩展了前文对非特征2域的结果。

Comments 59 pages

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AI中文摘要

设F为一个域,$\mathcal{M}$为一个n乘n矩阵的线性子空间,其元素在F中至多有两个特征值(分别地,至多有一个非零特征值)。在前一篇文章中,我们确定了当F的特征不为2时,$\mathcal{M}$的最大可能维度。在本文及其后续文章中,我们解决了所有特征为2的域的情况。

英文摘要

Let $F$ be a field, and $\mathcal{M}$ be a linear subspace of $n$-by-$n$ matrices with entries in $F$ that have at most two eigenvalues in $F$ (respectively, at most one non-zero eigenvalue in $F$). In a previous article, we have determined the greatest possible dimension for $\mathcal{M}$ when the characteristic of $F$ is not $2$. In this article and its sequel, we solve this problem for all fields with characteristic $2$.

2605.05845 2026-05-08 math.NA cs.NA

Mathematical and experimental validation of the bifocusing method tailored for bistatic measurement

双聚焦方法在双站测量中的数学和实验验证

Won-Kwang Park

AI总结 本文设计了基于双聚焦的成像策略,用于快速识别双站测量设置中二维小穿透介电不均匀体。通过建立涉及贝塞尔函数无穷级数、材料特性及双站角的关系,验证了双站角接近180度时成像分辨率下降,甚至无法识别目标,而接近0度时则能获得较高分辨率。

Comments 18 pages, 9 figures

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AI中文摘要

本文设计了一种基于双聚焦的成像策略,用于在双站测量设置中快速识别二维小穿透介电不均匀体。为了解决适用性和限制性问题,我们通过建立涉及贝塞尔函数无穷级数、材料特性及双站角的关系,深入探讨了指示函数的数学结构。通过这一理论结果,我们严格验证了当双站角接近180度时成像分辨率下降,且当双站角为180度时目标识别变得不可能。相反,当双站角接近0度时,可以获得相对较高的分辨率。理论发现通过使用弗雷斯涅尔实验数据集进行数值模拟得到验证,确认了所提出方法在介电和金属物体上的适用性和限制性。

英文摘要

In this paper, we design a bifocusing-based imaging strategy for the rapid identification of small penetrable dielectric inhomogeneities within a two-dimensional bistatic measurement setup. To address the applicability and limitation, we carefully explore the mathematical structure of the indicator function by establishing a relationship involving the infinite series of Bessel functions, the material characteristics, and the bistatic angle. Through this theoretical result, we rigorously verify that the imaging resolution degrades as the bistatic angle approaches $\SI{180}{\degree}$, and specifically, that target identification becomes impossible when the bistatic angle is $\SI{180}{\degree}$. Conversely, relatively high-resolution results are obtained when the bistatic angle is close to $\SI{0}{\degree}$. The theoretical findings are validated through numerical simulations using the Fresnel experimental dataset, which confirm the applicability and limitations of the proposed method for both dielectric and metallic objects.

2605.05844 2026-05-08 eess.SP cs.IT math.IT

TGPP: Trajectory-Guided Plug-and-Play Priors for Sparse Radio Map Reconstruction

TGPP:基于轨迹的插拔式先验用于稀疏射频地图重建

Jiawen Zhang, Zhiyuan Jiang, Sheng Zhou, Zhisheng Niu

AI总结 本文提出TGPP,一种基于轨迹的插拔式先验,用于改进稀疏射频地图重建的准确性,通过学习可解释的风险先验和隐式引导特征,提升不同重建模型的性能。

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AI中文摘要

射频地图(RM)重建对于环境感知无线网络至关重要,但实际测量通常是沿移动轨迹收集而非随机分布在目标区域。这种轨迹采样观测导致空间异质性不确定性:靠近轨迹区域直接受约束,而远处或被遮挡区域则弱观测,导致欠约束区域重建精度下降。为解决此问题,我们提出轨迹引导的插拔式先验(TGPP),一种通用的稀疏RM重建指导模块。TGPP学习显式的指导地图作为可解释的输入空间风险先验,并学习隐式的引导特征,将其投影并融合到主干隐藏表示中。TGPP可以附加到不同的重建主干上而不改变其原始任务公式。我们进一步引入RadioFlow-LDM,一种基于潜在流的生成主干,并将其应用于确定性、对抗性、图基和潜在生成重建模型。在RadioMapSeer上使用五种轨迹采样率的实验表明,轨迹采样重建与随机稀疏插值有显著差异。TGPP在所有主干上提升了大多数重建指标,相对于无轨迹引导先验的相应基础主干,实现了高达43.1%的NMSE减少。

英文摘要

Radio map (RM) reconstruction is essential for environment-aware wireless networks, but practical measurements are often collected along mobility trajectories rather than randomly scattered over the target region. Such trajectory-sampled observations induce spatially heterogeneous uncertainty: near-trajectory regions are directly constrained, whereas distant or occluded regions remain weakly observed, leading to degraded reconstruction accuracy in under-constrained areas. To address this problem, we propose Trajectory-Guided Plug-and-Play Priors (TGPP), a general guidance module for sparse RM reconstruction. TGPP learns an explicit guidance map as an interpretable input-space risk prior, and an implicit guide feature that is projected and fused with backbone hidden representations. TGPP can be attached to different reconstruction backbones without changing their original task formulation. We further introduce RadioFlow-LDM, a latent flow-based generative backbone, and apply TGPP to deterministic, adversarial, graph-based, and latent generative reconstruction models. Experiments on RadioMapSeer with five trajectory sampling rates show that trajectory-sampled reconstruction differs substantially from random sparse interpolation. TGPP improves most reconstruction metrics across backbones, achieving up to 43.1% NMSE reduction relative to the corresponding base backbone without trajectory-guided priors.

2605.05843 2026-05-08 cs.NI cs.SY eess.SY

Comparative Analysis of Direct-to-Cell (D2C) and 3GPP Non-Terrestrial Networks (NTN) for Global Connectivity

直接到终端(D2C)与3GPP非地面网络(NTN)的比较分析:为全球连接性服务

Donglin Wang, Anjie Qiu, Qiuheng Zhou, Hans D. Schotten

AI总结 本文比较了D2C和3GPP NTN两种架构,分析其标准化、网络架构、物理层创新及安全性和运营权衡,指出NTN在性能、安全性和扩展性上优于D2C,适合6G卫星-地面融合。

Comments 7 pages, 2 figures, IEEE VTC fall 2026

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AI中文摘要

为实现无处不在的移动覆盖,直接到终端(D2C)和标准化的3GPP非地面网络(NTN)两种根本不同的架构范式被推动。D2C由SpaceX Starlink和AST SpaceMobile率先采用,利用现有地面频谱和未经修改的消费手机提供应急连接作为市场驱动的叠加层。相比之下,3GPP NTN在Release 17-19中标准化,提供一个专为长期扩展、高吞吐量宽带和深入整合地面5G/6G网络而设计的卫星原生框架。本文全面比较了这两种方法,分析其标准化轨迹、网络架构、物理层创新、安全姿态和运营权衡。我们进一步探讨了它们对新兴6G用例的影响,特别是自动驾驶,其中安全关键的冗余性推动了结合地面5G、NTN宽带和D2C应急回退的混合三链架构。我们的分析表明,尽管D2C通过遗留设备兼容性实现快速市场进入,但NTN在性能、安全性和扩展性上更优,使其成为6G卫星-地面融合的基础框架。识别出结合两种范式优势的混合模型是实现真正全球连接的最实用路径。

英文摘要

The quest for ubiquitous mobile coverage has catalyzed two fundamentally distinct architectural paradigms: Direct-to-Cell (D2C) and standardized 3GPP Non-Terrestrial Networks (NTN). D2C, pioneered by SpaceX Starlink and AST SpaceMobile, leverages existing terrestrial spectrum and unmodified consumer handsets to provide emergency connectivity as a market-driven overlay. In contrast, 3GPP NTN, standardized across Releases 17-19, offers a systematic satellite-native framework designed for long-term scalability, high-throughput broadband, and deep integration with terrestrial 5G/6G networks. This paper presents a comprehensive technical comparison of these approaches, analyzing their standardization trajectories, network architectures, physical-layer innovations, security postures, and operational trade-offs. We further examine their implications for emerging 6G use cases, particularly autonomous driving, where safety-critical redundancy motivates a hybrid tri-link architecture combining terrestrial 5G, NTN broadband, and D2C emergency fallback. Our analysis shows that, although D2C enables rapid market entry through legacy-device compatibility, NTN provides superior performance, security, and scalability, positioning it as the foundational framework for 6G satellite-terrestrial convergence. A hybrid model that combines the strengths of both paradigms is identified as the most practical path toward truly global connectivity.

2605.05841 2026-05-08 quant-ph

Non-Abelian String-Breaking Dynamics on a Qudit Quantum Computer

非阿贝尔弦断裂动力学在量子门上

Manuel John, Keshav Pareek, Peter Tirler, Tim Gollerthan, Michael Meth, Lukas Gerster, Peter Zoller, Daniel González-Cuadra, Torsten V. Zache, Martin Ringbauer

AI总结 本文报告了在纯SU(2)格状规范理论中首次实现非阿贝尔弦断裂动力学的量子模拟,利用囚禁离子量子计算机进行实验研究。

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AI中文摘要

规范理论是粒子物理标准模型的基础。这些理论可以表现出约束,其中带电粒子只以束缚态形式出现,通过能量随分离距离线性增长的磁通弦连接。模拟此类弦的真实时间动力学,包括其断裂,仍然是经典计算的主要挑战,也是量子模拟的有希望目标。尽管最近的量子模拟实验探索了阿贝尔格状理论中的弦断裂动力学,非阿贝尔理论在本质上不同,因为规范场本身带有电荷。在这里,我们报告了在纯SU(2)格状规范理论中首次实现真正的非阿贝尔弦断裂动力学的量子模拟,其中规范场的自相互作用即使在没有动态物质的情况下也驱动弦断裂。我们的结果是在囚禁离子量子计算机上获得的,使用本机量子门希尔伯特空间来编码截断的规范场在阶梯几何结构中,并实现数字 Trotter 动力学。我们通过基本和伴随静态电荷分别生成不可断裂和可断裂的弦,并通过非阿贝尔plaquette相互作用驱动 gluonic 激发来局部解析弦振荡和相干弦断裂。我们的工作确立了硬件高效、问题特定的量子门模拟作为访问与高能物理相关的非微扰动力学的有希望的途径。

英文摘要

Gauge theories form the foundation of the Standard Model of particle physics. These theories can exhibit confinement, where charged particles only occur in bound states, connected by flux strings whose energy grows linearly with separation. Simulating the real-time dynamics of such strings, including their breaking, remains a major challenge for classical computations and a promising target for quantum simulations. While recent quantum simulation experiments explored string-breaking dynamics in abelian lattice gauge theories, non-abelian theories are qualitatively distinct because gauge fields themselves carry charge. Here, we report the first quantum simulation of genuine non-abelian string-breaking dynamics in a pure SU($2$) lattice gauge theory, where gauge-field self-interactions drive string breaking even in the absence of dynamical matter. Our results are obtained on a trapped-ion quantum computer, using native qudit Hilbert spaces to encode truncated gauge fields on a ladder geometry and implement digital Trotter dynamics. We experimentally study unbreakable and breakable strings generated by fundamental and adjoint static charges, respectively. We locally resolve string oscillations and coherent string breaking through the creation of gluonic excitations driven by non-abelian plaquette interactions. Our work establishes hardware-efficient, problem-tailored qudit simulations as a promising route for accessing non-perturbative dynamics relevant to high-energy physics.

2605.05839 2026-05-08 math.AP

Asymptotic properties of solutions to the characteristic problem for the ultrahyperbolic equation

特征问题的超双曲方程解的渐进行为

Maxim N. Demchenko

AI总结 研究超双曲方程在欧几里得空间中特征超平面数据下的解的光滑性及特征线上的渐进行为

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AI中文摘要

本文研究了超双曲方程在欧几里得空间中特征超平面上的数据问题。研究了解的光滑性及其沿与初始超平面正交的特征线上的渐进行为。

英文摘要

The paper concerns the problem for the ultrahyperbolic equation in the Euclidean space with data on a characteristic hyperplane. Smoothness and asymptotics of the solution along characteristic lines transversal to the initial hyperplane are investigated.

2605.05837 2026-05-08 cs.IT cs.DS math.IT

An Additive Approximation Scheme for Generating Dyadic Codings for the Outputs of an LLM

为LLM输出生成二进制编码的加性近似方案

Daniella Bar-Lev, Farzad Farnoud, Ryan Gabrys

AI总结 研究在编码速率约束下,通过二叉树诱导的二进制分布近似离散概率分布,提出多项式时间加性近似方案,提供近优二进制近似保证,并应用于LLM基隐写术。

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AI中文摘要

我们研究在编码速率约束下,通过二叉树诱导的二进制分布近似离散概率分布,如大语言模型的下一个令牌分布。目标是划分分布的支持集并分配二进制概率以最小化总变差距离同时达到指定速率。我们将此任务建模为基于树的划分问题,并在恒定速率范围内开发了一个多项式时间加性近似方案。我们的结果为近优二进制近似提供了可证明的保证,并作为应用,提供了基于LLM的隐写术原理框架,其中速率映射到每个令牌隐藏信息的位数,总变差界限控制统计可检测性。

英文摘要

We study the problem of approximating a discrete probability distribution, such as the next-token distribution of a large language model, by a dyadic distribution induced by a binary tree under encoding rate constraints. The objective is to partition the support of the distribution and assign dyadic probabilities to minimize total variation distance while achieving a prescribed rate. We formulate this task as a tree-based partitioning problem and develop a polynomial-time additive approximation scheme for the rate-constrained setting in the constant-rate regime. Our results provide provable guarantees for near-optimal dyadic approximations and, as an application, yield a principled framework for LLM-based steganography, where the rate maps to bits of hidden information embedded per token and the total variation bound controls statistical detectability.

2605.05836 2026-05-08 cs.HC

Can providing feedback on gaze and mental-effort synchrony improve pair programming performance?

提供注视和心理努力同步的反馈能否提高配对编程表现?

Anahita Golrang, Kshitij Sharma

AI总结 本文研究AI支持的反馈如何通过联合视觉注意和心理努力提升协作编程表现,探讨反馈时机对学习者与AI交互的影响。

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AI中文摘要

配对编程是计算机科学教育中广泛使用的协作学习实践,但其有效性因合作伙伴之间协调注意和认知调节的破裂而差异显著。本文探讨基于联合视觉注意和联合心理努力的AI支持反馈是否能提高协作编程表现,并研究反馈时机如何影响学习者与AI的交互。两项实验研究利用双目追踪捕捉调试任务中的实时协作调节指标。研究1检验了当观察到的联合视觉注意或联合心理努力偏离预设阈值时的反应式反馈;研究2评估了利用机器学习模型预测未来调节破裂并提前干预的前瞻性反馈。通过调试成功时间和反馈采纳(反映在代码更改中)评估反馈有效性。多模态反馈显著优于无反馈条件下的协作表现。反应式反馈在调试成功和效率上表现强劲,尤其当结合基于联合视觉注意和心理努力的反馈时。前瞻性反馈进一步提升表现,减少任务时间,增加建设性反馈采纳,同时依赖较少的侵入性干预。前瞻性反馈通过维持最优协作状态更好地保持学习者的自主性,尤其对高绩效配对而言。这些发现表明,注视和心理努力同步可以作为可靠的可操作触发器,用于AI支持的协作学习,突显了反馈时机透明度和前瞻性调节在支持有效配对编程中的重要性。

英文摘要

Pair programming is a widely used collaborative learning practice in computer science education yet its effectiveness varies substantially due to breakdowns in coordination attention and cognitive regulation between partners. This paper investigates whether AI supported feedback grounded in joint visual attention and joint mental effort can improve collaborative programming performance and how feedback timing shapes learner AI interaction. Two experimental studies using dual eye tracking capture real time indicators of collaborative regulation during debugging tasks. Study 1 examines reactive feedback that intervenes when observed joint visual attention or joint mental effort deviates beyond predefined thresholds while Study 2 evaluates proactive feedback that forecasts future regulatory breakdowns using machine learning models and intervenes pre emptively. Across both studies feedback effectiveness is assessed through debugging success time on task and feedback uptake reflected in code changes. Multimodal feedback significantly improves collaborative performance compared to no feedback conditions. Reactive feedback yields strong gains in debugging success and efficiency particularly when joint visual attention and joint mental effort based feedback are combined. Proactive forecast based feedback further enhances performance reduces time on task and increases constructive feedback uptake while relying less on intrusive interventions. Proactive feedback better preserves learner agency by maintaining optimal collaboration states, particularly for high-performing pairs. These findings demonstrate that gaze and mental effort synchrony can serve as reliable actionable triggers for AI supported collaborative learning highlighting the importance of feedback timing transparency and anticipatory regulation in supporting effective pair programming.