Artificial Intelligence · Cross-listed from cs.CY
From Celebrities to Anyone: Characterizing AI Nudification Content, Technology, and Community Dynamics on 4chan
Chi Cui, Yixin Wu and Yang Zhang
AI nudification uses generative models to create synthetic non-consensual sexually explicit imagery (SNEACI) of real individuals. Prior work has examined dedicated nudification platforms and model repositories, finding that most targets are female celebrities. However, the anonymous content community, where SNEACI is actively requested, generated, and exchanged, remains unexplored. In this work, we present a large-scale study of AI nudification in the wild, identifying 24,105 SNEACI items. We find a significant shift in target demographics: non-celebrity individuals now account for 55.8% of targets, compared to only 4.7% in prior studies, indicating that AI nudification has expanded from targeting public figures to increasingly harming individuals within users' own social circles. Meanwhile, open-source models dominate production, with Stable
Diffusion family generating 42.7% of images and Wan generating 66.5% of
videos, all driven by thousands of shared fine-tuned models and accessible tutorials. Yet the ecosystem runs on a small cohort of active producers, with the most prolific producing 780 items, drives community engagement, shapes target demographics, and disseminates technical knowledge that lowers barriers for new producers. Our work provides an empirical understanding of how AI nudification operates in the wild, revealing the mechanisms that sustain this ecosystem and highlighting the urgent need for interventions in platform governance, technical safeguards, and affected individual protection.
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Artificial Intelligence · Cross-listed from cs.CL
Bridging Talk and Thought: Understanding Dialogue Dynamics Across Collaborative Problem-Solving Contexts
Zhengyuan Liu, Stella Xin Yin, Min-Yen Kan et al. (+1 more)
We present a conceptual framework for analyzing dialogue in collaborative problem-solving contexts, with an emphasis on the emerging dynamics of human-AI and multi-
agent collaboration. As intelligent systems become active
agents capable of autonomous
reasoning and strategic cooperation, understanding the dialogic interaction during collaborative problem solving is increasingly important for optimizing and evaluating such partnerships. Our framework addresses key limitations in current analytical approaches through a hierarchical two-layer coding scheme that integrates cognitive and non-cognitive problem solving with metacognitive regulatory mechanisms. We demonstrate its effectiveness and generalizability across nine
datasets spanning multiple domains, and provide insights into how humans and
agents coordinate their knowledge, skills, and efforts to solve complex problems, showing in particular that metacognitive regulation can be an essential discriminator of deeper collaboration.
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All authors Zhengyuan Liu, Stella Xin Yin, Min-Yen Kan, Nancy F. Chen
Artificial Intelligence · Cross-listed from cs.CL
CARVE: Content-Aware Recurrent with Value Efficiency for Chunk-Parallel Linear Attention
Sayak Dutta
Recurrent delta-rule models keep a fixed-size state
matrix S (d_v x d_k) that compresses all past context. The state of the art (GDN-2) gates this update with element-wise
matrix erase/write masks. This is powerful but has two defects. First, both gates are computed from the incoming
token alone, making the model
memory-blind: it decides what to erase without seeing what it has stored. Second, value-axis coupling in the erase gate blocks the WY-form triangular chunk solver that drives efficient training – the intra-chunk system splits into d_v independent solves, collapsing throughput to serial-recurrence cost. We introduce CARVE (Content-Aware Recurrent with Value Efficiency), which fixes both and, via a single-launch "megakernel" scheduling of the same WY-form math, trains faster than the
matrix-gated baseline it replaces. The key idea is architectural: restricting all gating to the key axis makes the intra-chunk coupling independent of the value index, restoring one unmodified WY-form solve. Within this constraint, CARVE conditions both gates on a content signal read once per chunk from the chunk-boundary state and folded algebraically into each gate's low-rank projection (by associativity, U(Sq)=(US)q), giving
memory-aware gating at negligible extra traffic. At init the content projections are zero, so CARVE is bit-identical to the baseline; we prove the one-chunk staleness perturbs gates by only O(1/sqrt(L)), matching a measured 0.18% deviation flat up to L=128. At 1.3B parameters / 100B FineWeb-Edu
tokens on H100 (three seeds), CARVE improves every axis: WikiText perplexity 15.72 vs 15.90 (hybrid 15.41 vs 15.62), +0.63 pp average common-sense accuracy, and state-of-the-art RULER and real-world recall – while training +1.4% faster at matched depth and +19.3% at iso-quality depth, at +13% peak
memory. Backed by six formal guarantees.
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Artificial Intelligence
Ask, Don't Judge: Binary Questions for Interpretable LLM Evaluation and Self-Improvement
Sangwoo Cho, Kushal Chawla, Pengshan Cai et al. (+4 more)
Evaluating LLM outputs remains a major bottleneck in NLP: human evaluation is expensive and slow, lexical metrics correlate poorly with human judgments on open-ended generation, and holistic LLM judges often produce opaque scores that are hard to debug. We propose BINEVAL, a framework that decomposes evaluation criteria into atomic binary questions and aggregates the resulting verdicts into interpretable, multi-dimensional scores. Given a task
prompt, a meta-
prompt generates fine-grained evaluation questions, and an LLM answers them independently for each output, yielding transparent question-level feedback together with calibrated overall scores. This decomposition makes evaluation easier to inspect, easier to diagnose, and directly usable for
prompt improvement. Across SummEval, Topical-Chat, and QAGS, BINEVAL matches or outperforms strong baselines including UniEval and G-Eval, with especially strong results on factual consistency
benchmarks such as QAGS. Beyond competitive correlation with human judgments, BINEVAL better matches human score distributions and avoids the ceiling effects common in prior LLM judges, leading to better discrimination between borderline and clearly flawed outputs. We further show that the same question-level feedback supports iterative
prompt optimization, improving evaluator
prompts on summarization and generation
prompts on IFBench under both self-update and cross-model update settings. Overall, BINEVAL provides a task-agnostic, training-free, and interpretable evaluation framework that combines strong empirical performance with practical diagnostic and optimization value.
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All authors Sangwoo Cho, Kushal Chawla, Pengshan Cai, Zefang Liu, Chenyang Zhu, Shi-Xiong Zhang, Sambit Sahu
Artificial Intelligence
Vulnerability of Natural Language Classifiers to Evolutionary Generated Adversarial Text
Manjinder Singh, Alexander E. I. Brownlee and Mohamed Elawady
Deep learning models have achieved impressive performance across various fields but remain vulnerable to
adversarial inputs, particularly in NLP, where such attacks can have significant real-world consequences.
Adversarial attacks often involve small, semantically similar
token replacements to fool NLP models, and recent methods have become more precise by targeting specific vulnerable words, often by exploiting some level of access to the model's internal structure. This paper proposes GAversary, a hybrid Genetic
Algorithm (GA) to generate
adversarial attacks on natural
language models. The GA is able to treat the target model as a black box, requiring only the logit value output by the model to guide the search. GAversary differs from GAs previously proposed for this problem by using GloVe
embeddings to propose word replacements (the mutation operator) to improve the semantic similarity of the
adversarial examples. GAversary is applied to several
benchmark data sets and well-known target models. GAversary is able to substantially reduce the target model's accuracy on test data compared to the BAE and A2T attacks compared against (in the best case, reducing a 76.8% accuracy to 5.8%, compared to BAE's 27.6%). The trade-off is that GAversary perturbs just under twice as many words as the other two methods, with a slightly lower semantic similarity to the original text and around a 5% increase in run-time.
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Artificial Intelligence
A Process Harness for Uplifting Legacy Workflows to Agentic BPM: Design and Realization in CUGA FLO
Fabiana Fournier and Lior Limonad
We introduce the process harness, a new mechanism for uplifting legacy workflows into Agentic Business Process Management (Agentic BPM) without replacing the underlying workflow engine. A process harness places a policy-governed agentic layer around a deterministic workflow engine, intercepting designated control points to contribute
reasoning, adaptation, and oversight while the engine retains structural authority over the process. To define the process harness rigorously, we develop the Task-Decision-Flow (TDF) model, specifying both its data schema and its execution semantics. TDF decomposes LLM
reasoning across three policy-governed
agent types: a TaskAgent for knowledge-intensive task execution, a DecisionAgent for per-case gateway routing, and a FlowAgent that governs runtime flow adaptation through a principled hook mechanism. Each
agent reasons within an explicit policy drawn from the process FRAME, the aggregate policy set governing all LLM calls in the system. We then present CUGA FLO as the design and implementation realization of the TDF model, and demonstrate it on a loan approval workflow that exercises all three
agent types and hook-driven regulatory override. The process harness uniquely reconciles imperative requirements, realized through deterministic workflow execution that enforces structural compliance, with normative requirements, realized through policy-framed agentic autonomy invoked at designated control points wherever the process demands it.
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Artificial Intelligence · Cross-listed from cs.LG
Automating Potential-based Reward Shaping with Vision Language Model Guidance
Henrik Müller and Daniel Kudenko
Sparse rewards are inherently challenging for reinforcement learning
agents as they lack intermediate feedback to guide exploration and to correctly attribute the sparse success rewards to relevant parts of the trajectory. Naive reward shaping can induce reward hacking, yielding policies that exploit auxiliary signals instead of solving the intended task. Potential-based reward shaping (PBRS) guarantees preservation of the optimal policy set, but requires the definition of a heuristic potential function over the state space. In this work, we introduce the VLM-guided PBRS framework VLM-PBRS that learns the potential function directly from
vision language model (VLM) feedback. We query a lightweight VLM to obtain preferences over image pairs and train a model of the potential function using these preferences. As this approach is based on potential-based reward shaping, it preserves the original optimal policies, and removes the need for expert-designed reward shaping terms. Because large VLMs are prohibitively expensive to invoke repeatedly during policy learning, we employ smaller, more computationally efficient VLMs. Although the resulting preference labels are less accurate, empirical evidence shows that the preference labels can still be used to accelerate learning. We validate our method empirically in the Meta-World and Franka Kitchen environments and highlight the connection between VLM preference label accuracy and sample efficiency improvements. Our contributions are threefold: (1) the first application of VLM preference-based learning to synthesize a potential function for PBRS, (2) a principled, low-cost solution that leverages small VLMs, and (3) extensive empirical demonstration of improved sample efficiency and robustness to reward hacking.
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Artificial Intelligence · Cross-listed from cs.RO
Learning to Fold: prizewinning solution at LeHome Challenge 2026 (1st place online, 2nd offline)
Ilia Larchenko
I describe my solution to the LeHome Challenge 2026, an ICRA 2026 competition on bimanual garment folding. The system placed 1st of 62 teams in the online (simulation) round and 2nd in the real-world final. It improves a
vision-
language-action (VLA) policy with a reinforcement-learning loop. The policy is its own value function: the same network that predicts actions also predicts success, progress, and a few task-relevant future quantities, and those predictions drive advantage estimation, live failure detection, and candidate selection. The work mostly recombines existing RL ideas with engineering and optimization contributions that can be used together as one recipe or individually: AWR + RECAP combined for flow-matching VLA; an asynchronous distributed training / rollout pipeline through HuggingFace Hub; inference-time hyperparameters optimization via Thompson sampling; a sim-to-real recipe with camera-
alignment tooling, heavy augmentation and DAgger-like HIL data collection.
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Artificial Intelligence
TOPS: First-Principles Visual Token Pruning via Constructing Token Optimal Preservation Sets for Efficient MLLM Inference
Tinghao Wang, Yichen Guo, Rui Huang et al. (+9 more)
Multimodal large
language models (MLLMs) have achieved strong
multimodal reasoning capabilities, but their efficiency is limited by the large number of visual
tokens, which introduces substantial computational overhead. Visual
token pruning offers a natural solution, yet existing methods are imperfect:
attention-based criteria tend to retain redundant
tokens, while diversity-based criteria are often agnostic to user instructions. Even methods that combine multiple criteria still lack a principled formulation of the intrinsic objective of
token pruning. In this paper, we revisit visual
token pruning from a first-principles perspective and formulate it as constructing
Token Optimal Preservation Sets. Through a top-down information-theoretic analysis, we identify three fundamental principles for effective
token selection: Task Relevance, Information Coverage, and Semantic Diversity. Based on these principles, we propose TOPS, a training-free and model-agnostic
pruning module that can be applied to various MLLMs. Extensive experiments on 7 MLLM backbones and 14
benchmarks demonstrate that TOPS outperforms prior methods under diverse
pruning settings. Notably, on LLaVA-NeXT, TOPS removes 77.8% of visual
tokens while preserving 100.0% and 100.6% performance on its 7B and 13B models, respectively, suggesting that
pruning redundant visual
tokens can sometimes mitigate
hallucination and inspire future lightweight MLLM design. Our code is available at https://github.com/MAX-7237/TOPS.
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All authors Tinghao Wang, Yichen Guo, Rui Huang, Junchi Yao, Qizhe Zhang, Zheng Lu, Yuan Zhang, Jiajun Cao, Zhirong Shen, Yaosong Du, Lijie Hu, Shanghang Zhang
Artificial Intelligence
OpenRCA 2.0: From Outcome Labels to Causal Process Supervision
Aoyang Fang, Yifan Yang, Jin'ao Shang et al. (+7 more)
Root cause analysis (RCA) poses a holistic test of LLM agentic capabilities, such as long-context understanding, multi-step
reasoning, and tool use. However, existing
datasets suffer from a fundamental gap: they label only the root cause, not the propagation path connecting it to the observed symptom, which largely simplifies the task to naive pattern matching. To support rigorous evaluation, we introduce PAVE, a step-wise labeling protocol that leverages known interventions from fault injection to reconstruct causal propagation paths. The mechanism is forward verification:
reasoning from cause to effect rather than inferring backward from symptoms. Applying PAVE yields OpenRCA 2.0 (500 instances), the first cross-system RCA
benchmark with step-wise causal annotations for LLM
agents. Across 11 frontier LLMs, recovering the exact root-cause set succeeds in only 20.7% of cases on average. To locate where this difficulty lies, we relax the criterion and find what we call the ungrounded diagnosis:
agents identify at least one correct root-cause service in 76.0% of cases, but ground that service in a verified causal propagation path to the observed symptom in only 61.5%. Outcome-only evaluation hides this failure mode; step-wise causal ground truth is the missing piece for trustworthy LLM-based RCA
agents.
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All authors Aoyang Fang, Yifan Yang, Jin'ao Shang, Qisheng Lu, Junjielung Xu, Rui Wang, Songhan Zhang, Yuzhong Zhang, Boxi Yu, Pinjia He
Artificial Intelligence · Cross-listed from cs.CV
Safe Autoregressive Image Generation with Iterative Self-Improving Codebooks
Yunqi Xue, Zhijiang Li, Philip Torr et al. (+1 more)
Unlike
diffusion-based models that operate in continuous latent spaces, autoregressive unified
multimodal models produce images by sequentially predicting discretized visual
tokens. These
tokens are derived from a codebook that maps
embeddings to quantized visual patterns. The
language-like architecture enables unified
multimodal models to effectively capture text conditional information for generation, making them promising for text-to-image tasks. This also raises an interesting question: how safe are the images generated in such an autoregressive way? In this work, we propose iterative self-improving codebooks for safe autoregressive generation. We leverage the understanding and judgment capabilities of the unified
multimodal model itself to identify unsafe generated images without human annotation. Subsequently, the inherent representations in the codebook are fixed to eliminate harmful mappings. Our method comprises two steps: first, we use the unified model to identify unsafe generations and construct corresponding harmful and safe image-text pairs. These pairs are used to construct the Harmful Space and guide updates to the codebook, thereby eliminating harmful outputs. Second, we perform adaptive fine-tuning on the codebook within the harmless space using safe image-text pairs to ensure the quality of generated images. These two steps are repeated until no further improvement is observed, producing a safety-enhanced model codebook. Without additional external feedback, the safety of models is improved iteratively.
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All authors Yunqi Xue, Zhijiang Li, Philip Torr, Jindong Gu
Artificial Intelligence
Joint Learning of Experiential Rules and Policies for Large Language Model Agents
Shicheng Ye and Chao Yu
For LLM
agents in multi-step interactive environments, a key challenge is to make effective use of accumulated interaction experience. Existing work has typically separated two uses of such experience: keeping it outside the model as natural-
language rules for later prompting, or using trajectories and feedback to update the model parameters. The former is easy to interpret but can fall out of sync with the evolving policy; the latter improves the policy more broadly but provides only limited correction for local mistakes in sparse-reward settings. We present Joint Learning of Experiential Rules and Policies for LLM
Agents (JERP), which updates a long-term experiential-rule pool and the policy from the same interaction trajectories. At decision time, JERP retrieves task-relevant rules and conditions the
agent on them together with the interaction history. After each episode, it uses the collected trajectories both to optimize the policy and to revise the rule pool by comparing current rollouts with reference successful trajectories. This coupling keeps the rule pool aligned with the evolving policy while allowing stable and effective behaviors to be gradually absorbed into the model itself. Experiments on AlfWorld and WebShop show that JERP yields consistent gains in decision performance for complex interactive tasks.
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Artificial Intelligence · Cross-listed from quant-ph
Efficient foundation decoders for fault-tolerant quantum computing
Ge Yan, Shanchuan Li, Shiyi Xiao et al. (+4 more)
Foundation decoders, a class of high-capacity neural decoders, are leading candidates for fault-tolerant
quantum computing, with accurate and efficient decoding at large code distances. However, their construction often faces a steep scaling barrier, as larger code distances rapidly amplify the cost of syndrome generation and neural optimization. To address this bottleneck, here we devise neural transfer unification (NTU), a unified framework for efficient foundation decoders. A central feature of NTU is its ability to align decoding tasks across code distances via algebraic structures shared by scalable code families, which enables knowledge learned on smaller codes to accelerate large-scale decoder training. We instantiate NTU as NTU-
Transformer, a
transformer-based neural decoder tailored for planar surface codes and bivariate bicycle codes. For planar surface codes under
circuit-level noise, NTU-
Transformer outperforms correlation-aware matching on the $[\![361,1,19]\!]$ code and further scales to the $[\![625,1,25]\!]$ code, where it exceeds standard matching through transfer adaptation. For the bivariate bicycle code with $[\![72,12,6]\!]$, it surpasses Relay-BP in the low-physical-error regime. These results establish our proposal as a scalable route to amortized cross-distance training of foundation decoders for fault-tolerant
quantum processors.
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All authors Ge Yan, Shanchuan Li, Shiyi Xiao, Pengyue Ma, Hanyan Cao, Feng Pan, Yuxuan Du
Artificial Intelligence · Cross-listed from cs.LG
Heavy-Ball Q-Learning with Residual Weighting Correction
Donghwan Lee
This paper proposes a corrected heavy-ball Q-learning method for reinforcement learning (RL) and establishes convergence of its deterministic mean dynamics. It also identifies conditions under which the method is theoretically guaranteed to converge faster than standard Q-learning. The same construction is then extended to Q-learning with linear function approximation, where analogous convergence and acceleration statements are derived for the corresponding corrected fixed point. The sampled
stochastic versions are treated through conditional-mean recursions and, in the stated linear-function-approximation setting, finite-time bounds. The analysis is based on a switched linear system (SLS) representation of Q-learning
algorithms and on the joint spectral radius (JSR) of the associated switching families. This SLS viewpoint is not commonly used in standard analyses of Q-learning, and it provides a complementary framework and new insight into how heavy-ball momentum can accelerate Q-learning.
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Artificial Intelligence · Cross-listed from cs.CR
Application of LLMs to Threat Assessment of Foreign Peacekeeping Missions
Gerhard Backfried, Christian Schmidt, Diego Pilutti et al. (+1 more)
We present a novel approach for applying Large
Language Models (LLMs) to threat assessment in the context of foreign peacekeeping missions. Building on the PINPOINT project and its use case, the EU Monitoring Mission in Georgia, we combine an interdisciplinary risk-model with OSINT-based media collection and LLM-supported threat extraction. The proposed workflow maps media contents to mission-relevant threats, extracts structured information and applies several additional LLM-based processing steps to improve relevance and grounding. An evaluation of threats extracted from media documents shows high agreement between automatically generated results and human judgment for core aspects such as threat and mission relevance. These results indicate that LLMs provide a promising approach to support analysts in the context of peacekeeping missions.
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All authors Gerhard Backfried, Christian Schmidt, Diego Pilutti, Michael Suker
Artificial Intelligence · Cross-listed from cs.LG
Data-Free Reservoir Features for Efficient Long-Horizon Cold-Start Continual Learning
Augustinas Jučas and Yangchen Pan
Cold-start exemplar-free class-incremental learning requires learning a growing set of classes without replay, external pretraining, or a large initial task. Existing cold-start methods typically either train the backbone throughout the stream and compensate for semantic drift, or freeze a backbone after the first task, producing features biased toward the initial classes. These choices also create a computational tension: drift-compensation methods require repeated backbone training and increasingly expensive updates as the task horizon grows, while frozen-backbone methods are cheap but weak under cold start. We study a third option: a feature extractor that is never fit to image data at all. We propose CIRCLE, a class-incremental classifier built from fixed bidirectional two-dimensional reservoir features, adapted from BiRC2D for image classification, and streaming linear discriminant analysis heads. CIRCLE groups multiple random reservoir instantiations into feature ensembles and averages the softmax outputs of independent SLDA heads, yielding a tunable bias-variance tradeoff between richer random features and prediction-level ensembling. Because the feature extractor is fixed and the head admits streaming closed-form updates, CIRCLE performs sample-wise training without replay, task-boundary information, or backbone backpropagation. On CIFAR-100, TinyImageNet, ImageNet-Subset, and ImageNet-1k, CIRCLE is competitive at 10-20 task splits and substantially outperforms strong CS-EFCIL baselines at 50, 100, and 500 task splits, while training much faster than trained-backbone drift-compensation methods. Ablations show that the BiRC2D-style extractor, SLDA head, and balanced feature/prediction ensembling each contribute to the final performance.
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Artificial Intelligence · Cross-listed from cs.CR
Inherited Circuits, Learned Semantics: How Fine-Tuning Creates Evasion Vulnerabilities Invisible to Standard Evaluation
Ryan Fetterman
LLMs fine-tuned for security classification are usually evaluated on held-out examples from the same distribution as their training data. We show that this can miss vulnerabilities introduced by fine-tuning itself: models can learn
token-level indicator semantics that preserve canonical accuracy while failing under behavior-preserving transformations such as PowerShell alias substitution, command reconstruction, string construction, execution indirection, and case mutation. We study Foundation-Sec-8B-Instruct and its base model, Llama-3.1-8B-Instruct, on matched PowerShell classification cohorts. Causal interventions localize the classification
circuit to a late-
attention route inherited from Llama rather than created by fine-tuning. Fine-tuning concentrates and semantically specializes this inherited structure, improving baseline behavior while creating transformation-sensitive attack surfaces. A three-tier evasion
benchmark finds Foundation-Sec misses on iwr substitution, Invoke-Expression reconstruction, and case-mutated Invoke-Expression/IEX variants that Llama does not share. We also derive a pre-deployment monitoring method: a linear probe at the classification boundary and an indicator-
token sign test identify command families where canonical indicators change role after fine-tuning. These signals prioritize red-team variant generation using only canonical inputs, showing that security fine-tuning can improve task accuracy while expanding the evasion surface. These results caution against treating small task-specific fine-tunes as straightforwardly safer security classifiers: specialization can convert inherited model structure into brittle indicator rules that preserve held-out accuracy while expanding the evasion surface. Robust AI-enabled security will require specifying the full transformation space of the task and monitoring semantic drift through fine-tuning.
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Artificial Intelligence · Cross-listed from stat.ML
Beyond Global Divergences: A Local-Mass Perspective on Bayesian Inference
Hanli Xu, Fengxiang He and Sarat Moka
Global objectives, such as KL divergence and ELBO, are widely used in
Bayesian inference for measuring distributional discrepancy. This paper studies distributional “local-mass behaviours” that are not directly captured by such global objectives. We introduce and use two mathematical tools: (1) Mass Index for recording the
polynomial and logarithmic decay scales of local mass, and (2) regularised extended KL (RE-KL), a set-localised divergence that can be formulated in the presence of singular components. Mass Indices help characterise how
Bayesian updating changes local mass: (1) power-log likelihood factors shift it explicitly, and (2) parameter-dependent supports, or their smooth softenings, may change the local scale through the amount of mass that remains near the parameter value. Using local RE-KL, we prove absolute, relative, and directional inequalities for comparing local small-ball masses under the two KL directions. Together, these results provide a local theoretical account of local mass behaviour. Experiments provide controlled illustrations of the local behaviour, and show that the directional comparison remains visible in the variational posteriors of
Bayesian neural networks up to ResNet-50 on ImageNet. Code is available at https://github.com/Forsythia0604/Local-Mass-Framework.
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Artificial Intelligence · Cross-listed from cs.GT
Parametric Open Source Games
Aleksandar Todorov, Jesse ten Napel and Alexander Müller
Open-source game theory studies
agents whose behavior may depend on one another's decision procedures, but most existing models use discrete or symbolic programs. We introduce parametric open-source games, a continuous analogue of program
equilibria in which players choose parameter vectors and semantics maps convert the full parameter profile into mixed actions in an underlying finite game. We establish
equilibrium existence results, derive an exact coupling threshold at which selfish gradient ascent in symmetric $2\times2$ games switches from defection toward cooperation, and give a one-dimensional boundary test for parametric program Nash
equilibria. We further extend the framework to a neural semantics class whose first-order cooperation condition is governed by the ratio of cross-player to self-player sensitivity. Across canonical games, the framework shows how access to internal parameterizations can qualitatively reshape learning dynamics and
equilibrium structure, and how sufficiently strong open-source coupling can steer selfish optimization toward cooperative outcomes.
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Artificial Intelligence
How to evaluate clustering with ground truth?
Pasi Fränti
External indexes can be used for cluster evaluation when ground truth is available. We review the most common external validity indexes focusing on set-matching-based measures. We recommend centroid index (CI), because it is an intuitive cluster-level measure with an explainable result. If we need a more fine-tuned, point-level measure, there are more choices. Pair-set index (PSI) provides a normalized score which is not biased by cluster sizes. If all points should matter equally, then clustering accuracy (ACC) or any other set-matching measure is suitable.
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Artificial Intelligence · Cross-listed from cs.CL
NuclearQAv2: A Structured Benchmark for Evaluating Domain-Science Competence in Large Language Models
Henry Shaowu Yuchi, Michal Kucer, Benjamin H. Sims et al. (+2 more)
Large
language models (LLMs) have demonstrated strong performance across a wide range of tasks, but ensuring their reliability in highly technical domains remains a significant challenge. In
nuclear engineering, problem solving often requires not only factual knowledge but also quantitative
reasoning and conceptual understanding. To address the need for systematic evaluation in this domain, we introduce NuclearQAv2, a
benchmark for assessing LLMs on
nuclear engineering knowledge. The
benchmark comprises approximately 1,240 question-answer pairs spanning three categories: boolean, numeric, and verbal. NuclearQAv2 is constructed using a hybrid pipeline that combines expert-authored questions, existing
datasets, and LLM-assisted generation from domain-specific technical corpora. By leveraging structured prompting for both automated question generation and response evaluation, the proposed framework enables scalable
benchmark construction and evaluation. We evaluate a diverse set of LLMs using NuclearQAv2 and observe substantial performance differences across task types. While the models generally perform well on factual questions, quantitative
reasoning and conceptual understanding remain considerably more challenging. These results highlight the importance of multi-faceted evaluation frameworks and establish NuclearQAv2 as a scalable
benchmark for assessing LLM capabilities in technical domains.
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All authors Henry Shaowu Yuchi, Michal Kucer, Benjamin H. Sims, Selma Peterson, Emily Taylor
Artificial Intelligence · Cross-listed from cs.SE
The Spec Growth Engine: Spec-Anchored, Code-Coupled, Drift-Enforced Architecture for AI-Assisted Software Development
Hartwig Grabowski
AI coding
agents dramatically accelerate implementation speed but introduce two structural failure modes that existing spec-driven approaches do not fully solve: (1) context explosion – the
agent must reason over an entire repository at once, degrading output quality as the context window fills; and (2) silent spec-code drift – code evolves, the specification does not, and the divergence becomes invisible until it is costly to repair. We present the Spec Growth Engine, a lightweight framework that addresses both failure modes through a machine-readable spec graph whose nodes carry explicit contract/design separation, a Spine context assembler that scopes
agent context to an ownership path, a vertical-slice growth protocol that enforces hardest-first ordering, and a drift gate that makes spec-code divergence a blocking merge condition. The design synthesises well-established software engineering principles (Parnas information hiding, C4, ADRs, Walking Skeleton, Reflexion Models, Fitness Functions) into a lean, code-coupled, machine-enforced whole – without the overhead of heavy-weight frameworks such as RUP or MDA.
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Artificial Intelligence · Cross-listed from cs.LG
State Representation Matters in Deep Reinforcement Learning: Application to Energy Trading
Jesper Klicks, Sander Vržina and Vincent François-Lavet
Energy trading decisions depend not only on current
market prices, but also on expected future
market conditions, and operational constraints. This makes the state representation given to a reinforcement learning
agent an important design choice. We study this in HydroDam, a pumped-storage arbitrage environment, using a fixed Double DQN
agent. The environment, action space, reward function, network, and training protocol are kept fixed; only the
market features are changed. We compare absolute price/calendar features, relative features that compare current prices with recent
market history, forecast features, and all combinations of these three feature families. Policies are trained and selected using 2007–2011 Belgian day-ahead prices and evaluated on two test settings: a later same-
market test set from 2012–2025 and 39 other ENTSO-E
market zones. Absolute features only reaches 28.8% on the test set and a median 5.7% across zones. Relative-only and forecast-only states also stay below a rolling price-score heuristic in the cross-zone median. Combining feature families is much stronger: absolute + relative reaches 49.9% on the test set and a 39.8% cross-zone median, while absolute + relative + forecast reaches 55.6% and 47.5%. These results suggest that state representation is not a minor preprocessing choice in storage-trading RL, but a central part of the policy design: robust transfer requires combining price scale, recent relative price context, and short-horizon forecast information, rather than relying on any single feature family.
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Artificial Intelligence · Cross-listed from cs.CR
ShareLock: A Stealthy Multi-Tool Threshold Poisoning Attack Against MCP
Liwei Liu, Tianzhu Han, Zijian Liu et al. (+2 more)
With the rapid
evolution of LLM-driven
agents, Model Context Protocol (MCP), an open protocol bridging LLMs with external tools, has quickly become foundational to modern
agent ecosystems. However, the expanding adoption of MCP has also introduced novel security concerns such as Tool Poisoning Attack (TPA), which exploit LLM-server interactions to inject malicious
prompts. Existing poisoning schemes typically adopt a monolithic plaintext
embedding paradigm, which fails to withstand manual inspection or automated detectors. Current research still lacks a systematic analysis on multi-tool poisoning, where multiple tools can be exploited cooperatively to disperse detection risk. In this paper, we introduce ShareLock, a multi-tool threshold poisoning framework that utilizes Shamir's threshold scheme to ensure exceptional stealth and fault tolerance. ShareLock distributes the malicious instruction as benign-looking secret shares across multiple tool descriptions, achieving both information-theoretic secrecy and attack robustness against moderate
auditing. After a covert reconstruction trigger is planted during server update, the aggregated shares reconstruct the hidden instruction, resulting in critical breaches of system assets or private data. To evaluate the realistic threat of ShareLock, we constructed a comprehensive
benchmark encompassing four multi-tool scenarios and conducted extensive experiments across mainstream LLMs on two distinct MCP clients. Our results demonstrate that ShareLock significantly outperforms existing single-tool poisoning strategies in tool description-based detection while maintaining an average attack success rate exceeding 90%.
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All authors Liwei Liu, Tianzhu Han, Zijian Liu, Zishu Dong, Na Ruan
Artificial Intelligence · Cross-listed from cs.CV
On-board Remote-Sensing Foundation Models for Unsupervised Change Detection of Disaster Events
S. Ramírez-Gallego
Remote Sensing Foundation Models (RSFMs) have emerged as a powerful alternative to supervised models for Earth Observation, allowing satellites to autonomously trigger high-resolution captures or adjust tasking parameters upon detecting an anomaly, thereby maximizing the utility of the mission's limited power and computational resources. RSFMs are versatile, unified encoders that optimize onboard storage for multiple orbital applications while ensuring high-fidelity feature extraction. In particular, unsupervised change detection with RSFMs offers a well-informed and transformative path for disaster monitoring without expensive labels. In this paper, we present a novel unsupervised detection method based on ResNet (RSFM) + FPN which identifies a wide spectrum of anomalies by detecting subtle semantic shifts in the latent space between successive orbital passes. By relying on an untrained FPN architecture and its intrinsic priors, the system achieves efficient image-level generation and higher resolution mapping with minimal effort (training-free) compared to previous proposals (patch-based, trained). And by replacing tailored models with RSFMs, we can achieve comparable results through an approach that eliminates the need for bespoke training and extensive development effort and adds customization, while ensuring high-performance generalization across diverse terrains and sensors.
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Artificial Intelligence
Semantic Early-Stopping for Iterative LLM Agent Loops
Sahil Shrivastava
Multi-
agent large
language model (LLM) loops, for example a Writer that drafts and a Critic that revises, are almost always terminated by a fixed iteration cap (max_iterations). This is a syntactic kill-switch: it is blind to whether the answer is still improving, so it over-spends
tokens on easy inputs and truncates hard ones. We study semantic early-stopping: the loop halts when consecutive draft
embeddings stop changing in meaning (cosine distance with a patience window) and the answer's measured quality stops improving. Our work makes three contributions. First, an honest theoretical footing: we prove deterministic termination and well-definedness and machine-check these claims, while treating the convergence of the distance sequence as an empirically tested
conjecture rather than a (previously over-claimed)
Banach contraction. Second, a judge-efficient evaluation protocol: we generate each question's full trajectory once, replay every stopping policy over the identical drafts, and cache every LLM-judge call, yielding a strictly paired efficiency-versus-quality comparison at low cost; we further separate operational
tokens (charged to a policy) from evaluation
tokens (a measurement instrument). Third, an empirical study on multi-hop
retrieval-augmented question answering (HotpotQA). On the 60-question test split, a judge-free semantic stopper reduces operational
tokens by 38% relative to max_iterations at parity quality (Delta-IS = -0.004, p = 0.81), whereas the full quality-gated variant is counter-productive because its per-round judging dominates cost. An oracle that selects the best round attains +0.115 Information Score over every practical policy (p ~ 4e-11), reframing the problem from "when to stop" (easy) to "which round is best" (open).
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Artificial Intelligence
Adaptive Utility driven Resource Orchestration for Resilient AI (AURORA-AI)
Rahul Umesh Mhapsekar, Ilias Cherkaoui, Lizy Abraham et al. (+1 more)
Modern AI systems are increasingly deployed under non-stationary computational, demographic, and operational conditions in which static resource allocation strategies degrade both predictive performance and human-centric properties such as
fairness and explainability. This paper presents AURORA-AI, an Adaptive Utility-driven Resource Orchestration framework for Resilient AI that unifies Hamilton-Jacobi-Bellman feedback control, Lyapunov-based stability monitoring, and a
fairness-aware composite utility into a single closed-loop policy.The framework continuously redistributes computational budget across a population of heterogeneous AI models so that the global utility, defined jointly over predictive performance, demographic parity, cost, latency, robustness, and interpretability, remains maximised under disruption. The framework is evaluated in a stress-rich discrete-time simulation that concurrently injects demographic bias shocks, gradual concept drift, and abrupt black-swan disruptions, and is compared against five established controllers including Static, Round Robin, Greedy, LinUCB, and a deep reinforcement-learning
agent based on Proximal Policy Optimisation. AURORA-AI achieves immediate recovery from the black-swan event compared to eighty-eight time steps for the Static baseline and twenty-two for Proximal Policy Optimisation, lifts the alpha-
quantile and the super-
quantile by twenty-nine and twenty-five percent respectively, simultaneously reduces the mean and maximum demographic parity gap, and increases the fraction of Lyapunov-stable operating steps. These results indicate that
fairness-aware adaptive orchestration grounded in stability theory is a practical and theoretically motivated path toward resilient human-centric AI deployment.
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All authors Rahul Umesh Mhapsekar, Ilias Cherkaoui, Lizy Abraham, Indrakshi Dey
Artificial Intelligence · Cross-listed from eess.SP
Inverse Design of Compact and Wideband Inverted Doherty Power Amplifiers Using Deep Learning
Han Zhou, Haojie Chang, David Widen et al. (+1 more)
This paper presents a deep learning-assisted methodology for the inverse synthesis of a compact, wideband inverted Doherty power amplifier (PA). Convolutional neural networks (CNNs) and genetic
algorithms (GAs) are jointly employed to generate pixelated Doherty combiner networks that integrate load modulation, impedance matching, power combining, and phase compensation into a single structure. As a proof of concept, we design and fabricate a GaN HEMT Doherty PA with a pixelated output combiner. The prototype achieves a measured peak drain efficiency of 51%-63% and a 6-dB back-off efficiency of 48%-54% over 1.9-2.5 GHz. Within the same frequency range, the measured output power is 44+/-0.3 dBm. Furthermore, with digital predistortion (DPD) applied, the prototype
circuit demonstrates an adjacent channel leakage ratio (ACLR) better than -53.2 dBc.
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All authors Han Zhou, Haojie Chang, David Widen, Christian Fager
Artificial Intelligence · Cross-listed from cs.CV
Event-Aware Instructed Assistant for Referring Video Segmentation
Jinyu Liu, Henghui Ding, Shuting He et al. (+1 more)
Existing referring
video segmentation methods often treat a
video as a single event consisting of multiple images, overlooking the fact that a
video typically contains multiple distinct events. Under such a mechanism, the model needs to directly understand all the complex content in the
video and text, which can easily lead to confusion and
hallucinations. To address this issue, we propose to decompose a
video to a set of simple events by learnable Event Query, and understand complex
video content in an event-by-event, easy-to-understand manner. This is based on the observation that natural
language expressions often divide a
video into distinct, text-related segments, each representing a separate event within a compound event. We introduce EVIS, an Event-Aware
Video Instructed
Segmentation Assistant, which utilizes text-guided Event Queries to partition a
video into simple events, extracting event-aware visual-text features to achieve a hierarchical understanding of the
video. Additionally, we propose Object-Pixel-Hybrid Learning, which enables the MLLMs to track targets in long-term
videos by integrating fine-grained pixel features with prior object queries. Extensive experimental results on 5 public
benchmarks demonstrate EVIS's strong performance in addressing the referring
video segmentation task.
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All authors Jinyu Liu, Henghui Ding, Shuting He, Yu-Gang Jiang
Artificial Intelligence · Cross-listed from cs.LG
Decision-Aligned Evaluation of Uncertainty Quantification
Annika Schneider, Tommy Rochussen, Joshua Stiller et al. (+1 more)
Uncertainty estimates in machine learning are typically evaluated using generic metrics such as the negative log-likelihood and expected calibration error, yet good performance on such metrics does not necessarily imply high utility in downstream decisions. We introduce decision-
alignment, a criterion that reveals which evaluation metrics meaningfully align with downstream utilities. Applying this framework, we show that many widely used uncertainty metrics are either misaligned with common decision problems or encode pathological prior beliefs about the downstream task. We then propose prior-weighted utility metrics, a special class of proper scoring rules that provides decision-aligned uncertainty evaluation. Across
benchmark experiments and real-world case studies, our metrics consistently align with realized decision utility, while conventional metrics do not. Our results surface flaws in the current UQ evaluation protocol and offer a principled extension of existing metrics toward decision-relevant UQ evaluation.
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All authors Annika Schneider, Tommy Rochussen, Joshua Stiller, Vincent Fortuin