Systems and Control
C-IDS: Solving Contextual POMDP via Information-Directed Objective
Chongyang Shi, Michael Dorothy and Jie Fu
We study the policy synthesis problem in contextual partially observable Markov decision processes (CPOMDPs), where the environment is governed by an unknown latent context that induces distinct POMDP dynamics. Our goal is to design a policy that simultaneously maximizes cumulative return and actively reduces uncertainty about the underlying context. We introduce an information-directed objective that augments reward maximization with mutual information between the latent context and the
agent's observations. We develop the C-IDS
algorithm to synthesize policies that maximize the information-directed objective. We show that the objective can be interpreted as a Lagrangian relaxation of the linear information ratio and prove that the temperature parameter is an upper bound on the information ratio. Based on this characterization, we establish a sublinear
Bayesian regret bound over K episodes. We evaluate our approach on a continuous Light-Dark environment and show that it consistently outperforms standard POMDP solvers that treat the unknown context as a latent state variable, achieving faster context identification and higher returns.
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Image and Video Processing
CONRep: Uncertainty-Aware Vision-Language Report Drafting Using Conformal Prediction
Danial Elyassirad, Benyamin Gheiji, Mahsa Vatanparast et al. (+5 more)
Automated radiology report drafting (ARRD) using
vision-
language models (VLMs) has advanced rapidly, yet most systems lack explicit uncertainty estimates, limiting trust and safe clinical deployment. We propose CONRep, a model-agnostic framework that integrates conformal prediction (CP) to provide statistically grounded uncertainty quantification for VLM-generated radiology reports. CONRep operates at both the label level, by calibrating binary predictions for predefined findings, and the sentence level, by assessing uncertainty in free-text impressions via image-text semantic
alignment. We evaluate CONRep using both generative and contrastive VLMs on public chest X-ray
datasets. Across both settings, outputs classified as high confidence consistently show significantly higher agreement with radiologist annotations and ground-truth impressions than low-confidence outputs. By enabling calibrated confidence stratification without modifying underlying models, CONRep improves the transparency, reliability, and clinical usability of automated radiology reporting systems.
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All authors Danial Elyassirad, Benyamin Gheiji, Mahsa Vatanparast, Amir Mahmoud Ahmadzadeh, Seyed Amir Asef Agah, Mana Moassefi, Meysam Tavakoli, Shahriar Faghani
Audio and Speech Processing · Cross-listed from cs.CV
Audit After Segmentation: Reference-Free Mask Quality Assessment for Language-Referred Audio-Visual Segmentation
Jinxing Zhou, Yanghao Zhou, Yaoting Wang et al. (+5 more)
Language-referred audio-visual
segmentation (Ref-AVS) aims to segment target objects described by natural
language by jointly
reasoning over
video, audio, and text. Beyond generating
segmentation masks, providing rich and interpretable diagnoses of mask quality remains largely underexplored. In this work, we introduce Mask Quality Assessment in the Ref-AVS context (MQA-RefAVS), a new task that evaluates the quality of candidate
segmentation masks without relying on ground-truth annotations as references at inference time. Given audio-visual-
language inputs and each provided
segmentation mask, the task requires estimating its IoU with the unobserved ground truth, identifying the corresponding error type, and recommending an actionable quality-control decision. To support this task, we construct MQ-RAVSBench, a
benchmark featuring diverse and representative mask error modes that span both
geometric and semantic issues. We further propose MQ-Auditor, a
multimodal large
language model (MLLM)-based auditor that explicitly reasons over
multimodal cues and mask information to produce quantitative and qualitative mask quality assessments. Extensive experiments demonstrate that MQ-Auditor outperforms strong open-source and commercial MLLMs and can be integrated with existing Ref-AVS systems to detect
segmentation failures and support downstream
segmentation improvement. Data and codes will be released at https://github.com/jasongief/MQA-RefAVS.
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All authors Jinxing Zhou, Yanghao Zhou, Yaoting Wang, Zongyan Han, Jiaqi Ma, Henghui Ding, Rao Muhammad Anwer, Hisham Cholakkal
Audio and Speech Processing
Sounding Highlights: Dual-Pathway Audio Encoders for Audio-Visual Video Highlight Detection
Seohyun Joo and Yoori Oh
Audio-visual
video highlight detection aims to automatically identify the most salient moments in
videos by leveraging both visual and auditory cues. However, existing models often underutilize the audio modality, focusing on high-level semantic features while failing to fully leverage the rich, dynamic characteristics of sound. To address this limitation, we propose a novel framework, Dual-Pathway Audio Encoders for
Video Highlight Detection (DAViHD). The dual-pathway audio encoder is composed of a semantic pathway for content understanding and a dynamic pathway that captures spectro-temporal dynamics. The semantic pathway extracts high-level information by identifying the content within the audio, such as
speech, music, or specific sound events. The dynamic pathway employs a frequency-adaptive mechanism as time evolves to jointly model these dynamics, enabling it to identify transient acoustic events via salient spectral bands and rapid energy changes. We integrate the novel audio encoder into a full audio-visual framework and achieve new state-of-the-art performance on the large-scale MrHiSum
benchmark. Our results demonstrate that a sophisticated, dual-faceted audio representation is key to advancing the field of highlight detection.
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Image and Video Processing
To What Extent Do Token-Level Representations from Pathology Foundation Models Improve Dense Prediction?
Weiming Chen, Xitong Ling, Xidong Wang et al. (+10 more)
Pathology foundation models (PFMs) have rapidly advanced and are becoming a common backbone for downstream clinical tasks, offering strong transferability across tissues and institutions. However, for dense prediction (e.g.,
segmentation), practical deployment still lacks a clear, reproducible understanding of how different PFMs behave across
datasets and how adaptation choices affect performance and stability. We present PFM-DenseBench, a large-scale
benchmark for dense pathology prediction, evaluating 17 PFMs across 18 public
segmentation datasets. Under a unified protocol, we systematically assess PFMs with multiple adaptation and fine-tuning strategies, and derive insightful, practice-oriented findings on when and why different PFMs and tuning choices succeed or fail across heterogeneous
datasets. We release containers, configs, and
dataset cards to enable reproducible evaluation and informed PFM selection for real-world dense pathology tasks. Project Website: https://m4a1tastegood.github.io/PFM-DenseBench
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All authors Weiming Chen, Xitong Ling, Xidong Wang, Zhenyang Cai, Yijia Guo, Mingxi Fu, Ziyi Zeng, Minxi Ouyang, Jiawen Li, Yizhi Wang, Tian Guan, Benyou Wang, Yonghong He
Signal Processing
Digital-Twin Empowered Deep Reinforcement Learning For Site-Specific Radio Resource Management in NextG Wireless Aerial Corridor
Pulok Tarafder, Zoheb Hassan, Imtiaz Ahmed et al. (+3 more)
Joint base station (BS) association and beam selection in multi-
UAV aerial corridors constitutes a challenging
radio resource management (RRM) problem. It is driven by high-dimensional action spaces, need for substantial overhead to acquire global channel state information (CSI), rapidly varying propagation channels, and stringent latency requirements. Conventional combinatorial optimization methods, while near-optimal, are computationally prohibitive for real-time operation in such dynamic environments. While learning-based approaches can mitigate computational complexity and CSI overhead, the need for extensive site-specific (SS)
datasets for model training remains a key challenge. To address these challenges, we develop a Digital Twin (DT)-enabled two-stage optimization framework that couples physics-based beam gain modeling with DRL for scalable online decision-making. In the first stage, a channel twin (CT) is constructed using a high-fidelity ray-tracing solver with geo-spatial contexts, and network information to capture SS propagation characteristics, and dual annealing
algorithm is employed to precompute optimal transmission beam directions. In the second stage, a Multi-Head Proximal Policy Optimization (MH-PPO)
agent, equipped with a scalable multi-head actor-critic architecture, is trained on the DT-generated channel
dataset to directly map complex channel and beam states to jointly execute
UAV-BS-beam association decisions. The proposed PPO
agent achieves a 44%-121% improvement over DQN and 249%-807% gain over traditional heuristic based optimization schemes in a dense
UAV scenario, while reducing inference latency by several orders of magnitude. These results demonstrate that DT-driven training pipelines can deliver high-performance, low-latency RRM policies tailored to SS deployments suitable for real-time resource management in next-generation aerial corridor networks.
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All authors Pulok Tarafder, Zoheb Hassan, Imtiaz Ahmed, Danda B. Rawat, Kamrul Hasan, Cong Pu
Audio and Speech Processing
Conditional Flow Matching for Visually-Guided Acoustic Highlighting
Hugo Malard, Gael Le Lan, Daniel Wong et al. (+3 more)
Visually-guided acoustic highlighting seeks to rebalance audio in
alignment with the accompanying
video, creating a coherent audio-visual experience. While visual saliency and enhancement have been widely studied, acoustic highlighting remains underexplored, often leading to misalignment between visual and auditory focus. Existing approaches use discriminative models, which struggle with the inherent ambiguity in audio remixing, where no natural one-to-one mapping exists between poorly-balanced and well-balanced audio mixes. To address this limitation, we reframe this task as a generative problem and introduce a Conditional Flow Matching (CFM) framework. A key challenge in iterative flow-based generation is that early prediction errors – in selecting the correct source to enhance – compound over steps and push trajectories off-
manifold. To address this, we introduce a rollout loss that penalizes drift at the final step, encouraging self-correcting trajectories and stabilizing long-range flow integration. We further propose a conditioning module that fuses audio and visual cues before vector field regression, enabling explicit cross-modal source selection. Extensive quantitative and qualitative evaluations show that our method consistently surpasses the previous state-of-the-art discriminative approach, establishing that visually-guided audio remixing is best addressed through generative modeling.
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All authors Hugo Malard, Gael Le Lan, Daniel Wong, David Lou Alon, Yi-Chiao Wu, Sanjeel Parekh
Systems and Control
Mitigating Timing-Based Attacks in Real-Time Cyber-Physical Systems
Arkaprava Sain, Sunandan Adhikary and Soumyajit Dey
Real-time cyber-physical systems depend on deterministic task execution to guarantee safety and correctness. Unfortunately, this determinism can unintentionally expose timing information that enables adversaries to infer task execution patterns and carry out timing-based attacks targeting safety-critical control tasks. While prior defenses aim to obscure schedules through randomization or isolation, they typically neglect the implications of such modifications on closed-loop control behavior and real-time feasibility. This work studies the problem of securing real-time control workloads against timing inference attacks while explicitly accounting for both schedulability constraints and control performance requirements. We present a scheduling-based mitigation approach that introduces bounded timing perturbations to control task executions in a structured manner, reducing
adversarial opportunities without violating real-time guarantees. The framework jointly considers worst-case execution behavior and the impact of execution delays on control performance, enabling the system to operate within predefined safety and performance limits. Through experimental evaluation on representative task sets and control scenarios, the proposed approach demonstrates that exposure to timing-based attacks can be significantly reduced while preserving predictable execution and acceptable control quality.
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Signal Processing
A Narrowband Fully-Analog Multi-Antenna Transmitter
Nikola Zlatanov
This paper proposes a narrowband fully-analog $N$-
antenna transmitter that emulates the functionality of a narrowband fully-digital $N$-
antenna transmitter. Specifically, in symbol interval $m$, the proposed fully-analog transmitter synthesizes an arbitrary complex excitation vector $\boldsymbol{x}[m]\in\mathbb{C}^N$ with prescribed total power $\|\boldsymbol{x}[m]\|_2^2=P$ from a single RF tone, using only tunable phase-control elements embedded in a passive interferometric programmable network. The programmable network is excited through one input port while the remaining $N-1$ input ports are impedance matched. In the ideal lossless case, the network transfer is
unitary and therefore redistributes RF power among
antenna ports without dissipative amplitude control. The synthesis task is posed as a
unitary state-preparation problem: program a
unitary family so that $\boldsymbol{V}(\boldsymbol{\varphi}[m])\boldsymbol{e}_1=\boldsymbol{c}[m]$, where $\boldsymbol{c}[m]=\boldsymbol{x}[m]/\sqrt{P}$ and $\|\boldsymbol{c}[m]\|_2=1$. We provide a parameter-minimal realization and a closed-form programming rule: a balanced binary magnitude-splitting tree allocates the desired per-
antenna magnitudes $|c_n|$ using $N-1$ tunable split ratios, and a per-
antenna output phase bank assigns the target phases using $N$ tunable phase shifts. The resulting architecture uses exactly $2N-1$ real tunable degrees of freedom and admits a deterministic $O(N)$ programming procedure with no iterative optimization, enabling symbol-by-symbol updates. Using representative COTS components, we model the compute-excluded RF-front-end DC power of the proposed fully-analog transmitter and compare it against an equivalent COTS fully-digital array. For $N\le 16$, the comparison indicates significant RF-front-end power savings for the fully-analog architecture under a common delivered
antenna-port power normalization.
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Signal Processing
VR-VFL: Joint Rate and Client Selection for Vehicular Federated Learning Under Imperfect CSI
Metehan Karatas, Subhrakanti Dey, Christian Rohner et al. (+1 more)
Federated learning in vehicular edge networks faces major challenges in efficient resource allocation, largely due to high vehicle mobility and the presence of imperfect channel state information. Many existing methods oversimplify these realities, often assuming fixed communication rounds or ideal channel conditions, which limits their effectiveness in real-world scenarios. To address this, we propose variable rate vehicular
federated learning (VR-VFL), a novel
federated learning method designed specifically for vehicular networks under imperfect channel state information. VR-VFL combines dynamic client selection with adaptive transmission rate selection, while also allowing round times to flex in response to changing wireless conditions. At its core, VR-VFL is built on a bi-objective optimization framework that strikes a balance between improving learning convergence and minimizing the time required to complete each round. By accounting for both the challenges of mobility and realistic wireless constraints, VR-VFL offers a more practical and efficient approach to
federated learning in vehicular edge networks. Simulation results show that the proposed VR-VFL scheme achieves convergence approximately 40% faster than other methods in the literature.
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All authors Metehan Karatas, Subhrakanti Dey, Christian Rohner, Jose Mairton Barros da Silva Jr
Systems and Control
Input-to-State Safe Backstepping: Robust Safety-Critical Control with Unmatched Uncertainties
Max H. Cohen, Pio Ong and Aaron D. Ames
Guaranteeing safety in the presence of unmatched disturbances – uncertainties that cannot be directly canceled by the control input – remains a key challenge in nonlinear control. This paper presents a constructive approach to safety-critical control of nonlinear systems with unmatched disturbances. We first present a generalization of the input-to-state safety (ISSf) framework for systems with these uncertainties using the recently developed notion of an Optimal Decay CBF, which provides more flexibility for satisfying the associated Lyapunov-like conditions for safety. From there, we outline a procedure for constructing ISSf-CBFs for two relevant classes of systems with unmatched uncertainties: i) strict-feedback systems; ii) dual-relative-degree systems, which are similar to differentially flat systems. Our theoretical results are illustrated via numerical simulations of an inverted pendulum and planar quadrotor.
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Image and Video Processing · Cross-listed from cs.CV
Efficient Sequential Neural Network with Spatial-Temporal Attention and Linear LSTM for Robust Lane Detection Using Multi-Frame Images
Sandeep Patil, Yongqi Dong, Haneen Farah et al. (+1 more)
Lane detection is a crucial perception task for all levels of automated vehicles (AVs) and Advanced Driver Assistance Systems, particularly in mixed-traffic environments where AVs must interact with human-driven vehicles (HDVs) and challenging traffic scenarios. Current methods lack versatility in delivering accurate, robust, and real-time compatible lane detection, especially
vision-based methods often neglect critical regions of the image and their spatial-temporal (ST) salience, leading to poor performance in difficult circumstances such as serious occlusion and dazzle lighting. This study introduces a novel sequential neural network model with a spatial-temporal
attention mechanism to focus on key features of lane lines and exploit salient ST correlations among continuous image frames. The proposed model, built on a standard encoder-decoder structure and common neural network backbones, is trained and evaluated on three large-scale open-source
datasets. Extensive experiments demonstrate the strength and robustness of the proposed model, outperforming state-of-the-art methods in various testing scenarios. Furthermore, with the ST
attention mechanism, the developed sequential neural network models exhibit fewer parameters and reduced Multiply-Accumulate Operations (MACs) compared to baseline sequential models, highlighting their computational efficiency. Relevant data, code, and models are released at https://doi.org/10.4121/4619cab6-ae4a-40d5-af77-582a77f3d821.
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All authors Sandeep Patil, Yongqi Dong, Haneen Farah, Hans Hellendoorn
Systems and Control
A Comparison of Set-Based Observers for Nonlinear Systems
Nico Holzinger and Matthias Althoff
Set-based state estimation computes sets of states consistent with a system model given bounded sets of disturbances and noise. Bounding the set of states is crucial for safety-critical applications so that one can ensure that all specifications are met. While numerous approaches have been proposed for nonlinear discrete-time systems, a unified evaluation under comparable conditions is lacking. This paper reviews and implements a representative selection of set-based observers within the CORA framework. To provide an objective comparison, the methods are evaluated on common
benchmarks, and we examine computational effort, scalability, and the conservatism of the resulting state bounds. This study highlights characteristic trade-offs between observer categories and set representations, as well as practical considerations arising in their implementation. All implementations are made publicly available to support reproducibility and future development. This paper thereby offers the first broad, tool-supported comparison of guaranteed state
estimators for nonlinear discrete-time systems.
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Signal Processing
A Multi-decoder Neural Tracking Method for Accurately Predicting Speech Intelligibility
Rien Sonck, Bernd Accou, Tom Francart et al. (+1 more)
Objective:
EEG-based methods can predict
speech intelligibility, but their accuracy and robustness lag behind behavioral tests, which typically show test-retest differences under 1 dB. We introduce the multi-decoder method to predict
speech reception thresholds (SRTs) from
EEG recordings, enabling objective assessment for populations unable to perform behavioral tests; such as those with disorders of consciousness or during hearing aid fitting. Approach: The method aggregates data from hundreds of decoders, each trained on different
speech features and
EEG preprocessing setups to quantify neural tracking (NT) of
speech signals. Using data from 39 participants (ages 18-24), we recorded 29 minutes of
EEG per person while they listened to
speech at six signal-to-noise ratios and a quiet story. NT values were combined into a high-dimensional feature vector per subject, and a support vector regression model was trained to predict SRTs from these vectors. Main Result: Predictions correlated significantly with behavioral SRTs (r = 0.647, p < 0.001; NRMSE = 0.19), with all differences under 1 dB. SHAP analysis showed theta/delta bands and early lags had slightly greater influence. Using pretrained subject-independent decoders reduced required
EEG data collection to 15 minutes (3 minutes of story, 12 minutes across six SNR conditions) without losing accuracy.
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All authors Rien Sonck, Bernd Accou, Tom Francart, Jonas Vanthornhout
Signal Processing
Statistics Approximation-Enabled Distributed Beamforming for Cell-Free Massive MIMO
Zhe Wang, Emil Björnson, Jiayi Zhang et al. (+3 more)
We study a distributed beamforming approach for
cell-free massive multiple-input multiple-output networks, referred to as Global Statistics & Local Instantaneous information-based minimum mean-square error (GSLI-MMSE). The scenario with multi-
antenna access points (APs) is considered over three different channel models: correlated Rician fading with fixed or random line-of-sight (LoS) phase-shifts, and correlated Rayleigh fading. With the aid of
matrix inversion derivations, we can construct the conventional MMSE combining from the perspective of each AP, where global instantaneous information is involved. Then, for an arbitrary AP, we apply the statistics approximation methodology to approximate instantaneous terms related to other APs by channel statistics to construct the distributed combining scheme at each AP with local instantaneous information and global statistics. With the aid of uplink-downlink duality, we derive the respective GSLI-MMSE precoding schemes. Numerical results showcase that the proposed GSLI-MMSE scheme demonstrates performance comparable to the optimal centralized MMSE scheme, under the stable LoS conditions, e.g., with static users having Rician fading with a fixed LoS path.
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All authors Zhe Wang, Emil Björnson, Jiayi Zhang, Peng Zhang, Vitaly Petrov, Bo Ai
Signal Processing
Low-Complexity Distributed Combining Design for Near-Field Cell-Free XL-MIMO Systems
Zhe Wang, Jiayi Zhang, Bokai Xu et al. (+4 more)
In this paper, we investigate the low-complexity distributed combining scheme design for near-field
cell-free extremely large-scale multiple-input-multiple-output (CF XL-
MIMO) systems. Firstly, we construct the uplink spectral efficiency (SE) performance analysis framework for CF XL-
MIMO systems over centralized and distributed processing schemes. Notably, we derive the centralized minimum mean-square error (CMMSE) and local minimum mean-square error (LMMSE) combining schemes over arbitrary channel
estimators. Then, focusing on the CMMSE and LMMSE combining schemes, we propose five low-complexity distributed combining schemes based on the
matrix approximation methodology or the symmetric successive over relaxation (SSOR)
algorithm. More specifically, we propose two
matrix approximation methodology-aided combining schemes: Global Statistics & Local Instantaneous information-based MMSE (GSLI-MMSE) and Statistics
matrix Inversion-based LMMSE (SI-LMMSE). These two schemes are derived by approximating the global instantaneous information in the CMMSE combining and the local instantaneous information in the LMMSE combining with the global and local statistics information by asymptotic analysis and
matrix expectation approximation, respectively. Moreover, by applying the low-complexity SSOR
algorithm to iteratively solve the
matrix inversion in the LMMSE combining, we derive three distributed SSOR-based LMMSE combining schemes, distinguished from the applied information and initial values.
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All authors Zhe Wang, Jiayi Zhang, Bokai Xu, Dusit Niyato, Bo Ai, Shiwen Mao, Zhu Han
Signal Processing
Channel-Aware Conditional Diffusion Model for Secure MU-MISO Communications
Tong Hui, Xiao Tang, Yichen Wang et al. (+3 more)
While information securityis a fundamental requirement for wireless communications, conventional optimization based approaches often struggle with real-time implementation, and deep models, typically discriminative in nature, may lack the ability to cope with unforeseen scenarios. To address this challenge, this paper investigates the design of legitimate beamforming and artificial noise (AN) to achieve physical layer security by exploiting the conditional
diffusion model. Specifically, we reformulate the security optimization as a conditional generative process, using a
diffusion model to learn the inherent distribution of near-optimal joint beamforming and AN strategies. We employ a U-Net architecture with cross-
attention to integrate channel state information, as the basis for the generative process. Moreover, we fine-tune the trained model using an objective incorporating the sum secrecy rate such that the security performance is further enhanced. Finally, simulation results validate the learning process convergence and demonstrate that the proposed generative method achieves superior secrecy performance across various scenarios as compared with the baselines.
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All authors Tong Hui, Xiao Tang, Yichen Wang, Qinghe Du, Dusit Niyato, Zhu Han
Systems and Control
Real-world energy data of 200 feeders from low-voltage grids with metadata in Germany over two years
Manuel Treutlein, Pascal Bothe, Marc Schmidt et al. (+4 more)
The last mile of the distribution grid is crucial for a successful energy transition, as more low-carbon technology like photovoltaic systems, heat pumps, and electric vehicle chargers connect to the low-voltage grid. Despite considerable challenges in operation and planning, researchers often lack access to suitable low-voltage grid data. To address this, we present the FeederBW
dataset with data recorded by the German distribution system operator Netze BW. It offers real-world energy data from 200 low-voltage feeders over two years (2023-2025) with weather information and detailed metadata, including changes in low-carbon technology installations. The
dataset includes feeder-specific details such as the number of housing units, installed power of low-carbon technology, and aggregated industrial energy data. Furthermore, high photovoltaic feed-in and one-minute temporal resolution makes the
dataset unique. FeederBW supports various applications, including machine learning for load
forecasting, conducting non-intrusive load monitoring, generating synthetic data, and analyzing the interplay between weather, feeder measurements, and metadata. The
dataset reveals insightful patterns and clearly reflects the growing impact of low-carbon technology on low-voltage grids.
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All authors Manuel Treutlein, Pascal Bothe, Marc Schmidt, Roman Hahn, Oliver Neumann, Ralf Mikut, Veit Hagenmeyer
Systems and Control · Cross-listed from math.OC
A necessary and sufficient condition for discrete-time consensus on star boundaries
Galina Sidorenko and Johan Thunberg
It is intuitive and well known, that if
agents in a multi-
agent system iteratively update their states in the Euclidean space as convex combinations of neighbors' states, all states eventually converge to the same value (consensus), provided the interaction graph is sufficiently connected. However, this seems to be also true in practice if the convex combinations of states are mapped or radially projected onto any unit $l_p$-sphere or even boundaries of
star-convex sets, herein referred to as
star boundaries. In this paper, we present insight into this matter by providing a necessary and sufficient condition for asymptotic consensus of the normalized states (directions) for strongly connected directed graphs, which is equivalent to asymptotic consensus of states when the
star boundaries are the same for all
agents. Furthermore, we show that when asymptotic consensus occurs, the states converge linearly and the point of convergence is continuous in the initial states. Assuming a directed strongly connected graph provides a more general setting than that considered, for example, in gradient-based consensus protocols, where symmetric graphs are assumed. Illustrative examples and a vast number of numerical simulations showcase the theoretical results.
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Signal Processing
Multipath Extended Target Tracking with Labeled Random Finite Sets
Guanhua Ding, Qinchen Wu, Jinping Sun et al. (+3 more)
High-resolution radar sensors are critical for autonomous systems but pose significant challenges to traditional tracking
algorithms due to the generation of multiple measurements per object and the presence of multipath effects. Existing solutions often rely on the point target assumption or treat multipath measurements as clutter, whereas current extended target trackers often lack the capability to maintain trajectory continuity in complex multipath environments. To address these limitations, this paper proposes the multipath extended target generalized labeled multi-Bernoulli (MPET-GLMB) filter. A unified
Bayesian framework based on labeled random finite set theory is derived to jointly model target existence, measurement partitioning, and the association between measurements, targets, and propagation paths. This formulation enables simultaneous trajectory estimation for both targets and reflectors without requiring heuristic post-processing. To enhance computational efficiency, a joint prediction and update implementation based on Gibbs sampling is developed. Furthermore, a measurement-driven adaptive birth model is introduced to initialize tracks without prior knowledge of target positions. Experimental results from simulated scenarios and real-world automotive radar data demonstrate that the proposed filter outperforms state-of-the-art methods, achieving superior state estimation accuracy and robust trajectory maintenance in dynamic multipath environments.
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All authors Guanhua Ding, Qinchen Wu, Jinping Sun, Yanping Wang, Bing Zhu, Guoqiang Mao
Systems and Control · Cross-listed from math.OC
Cholesky factorisation, and intrinsically sparse linear quadratic regulation
Julia Adlercreutz and Richard Pates
We classify a family of
matrices of shift operators that can be factorised in a computationally tractable manner with the Cholesky
algorithm. Such
matrices arise in the linear quadratic regulator problem, and related areas. We use the factorisation to uncover intrinsic sparsity properties in the control laws for transportation problems with an underlying tree structure. This reveals that the optimal control can be applied in a distributed manner that is obscured by standard solution methods.
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Systems and Control
When control meets large language models: From words to dynamics
Komeil Nosrati, Aleksei Tepljakov, Juri Belikov et al. (+1 more)
While large
language models (LLMs) are transforming engineering and technology through enhanced control capabilities and decision support, they are simultaneously evolving into complex dynamical systems whose behavior must be regulated. This duality highlights a reciprocal connection in which
prompts support control system design while control theory helps shape
prompts to achieve specific goals efficiently. In this study, we frame this emerging interconnection of LLM and control as a bidirectional continuum, from
prompt design to system dynamics. First, we investigate how LLMs can advance the field of control in two distinct capacities: directly, by assisting in the design and synthesis of controllers, and indirectly, by augmenting research workflows. Second, we examine how control concepts help LLMs steer their trajectories away from undesired meanings, improving reachability and
alignment via input optimization, parameter editing, and activation-level interventions. Third, we look into deeper integrations by treating LLMs as dynamic systems within a state-space framework, where their internal representations are closely linked to external control loops. Finally, we identify key challenges and outline future research directions to understand LLM behavior and develop interpretable and controllable LLMs that are as trustworthy and robust as their electromechanical counterparts, thereby ensuring they continue to support and safeguard society.
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All authors Komeil Nosrati, Aleksei Tepljakov, Juri Belikov, Eduard Petlenkov
Audio and Speech Processing
A Unified SVD-Modal Solution for Sparse Sound Field Reconstruction with Hybrid Spherical-Linear Microphone Arrays
Shunxi Xu, Thushara Abhayapala and Craig T. Jin
We propose a data-driven sparse recovery framework for hybrid spherical linear microphone arrays using singular value decomposition (SVD) of the transfer operator. The SVD yields orthogonal microphone and field modes, reducing to spherical harmonics (SH) in the SMA-only case, while incorporating LMAs introduces complementary modes beyond SH. Modal analysis reveals consistent divergence from SH across frequency, confirming the improved spatial selectivity. Experiments in reverberant conditions show reduced energy-map mismatch and angular error across frequency, distance, and source count, outperforming SMA-only and direct concatenation. The results demonstrate that SVD-modal processing provides a principled and unified treatment of hybrid arrays for robust sparse sound-field reconstruction.
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Systems and Control
Dynamics of Implicit Time-Invariant Max-Min-Plus-Scaling Discrete-Event Systems
Sreeshma Markkassery, Ton van den Boom and Bart De Schutter
Max-min-plus-scaling (MMPS) systems generalize max-plus, min-plus and max-min-plus models with more flexibility in modelling discrete-event dynamics. Especially, implicit MMPS models capture a wide range of real world discrete-event applications. This article analyzes the dynamics of an autonomous, time-invariant implicit MMPS system in a discrete-event framework. First, we provide sufficient conditions under which an implicit MMPS system admits at least one solution to its state-space representation. Then, we analyze its global behavior by determining the key parameters; the growth rates and fixed points. For a solvable MMPS system, we assess the local behavior of the system around its set of fixed points via a normalization procedure. Further, we present the notion of stability for the normalized system. A case study of the urban railway network substantiates the theoretical results.
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Image and Video Processing · Cross-listed from cs.CV
LEVIO: Lightweight Embedded Visual Inertial Odometry for Resource-Constrained Devices
Jonas Kühne, Christian Vogt, Michele Magno et al. (+1 more)
Accurate, infrastructure-less sensor systems for motion tracking are essential for mobile robotics and augmented reality (AR) applications. The most popular state-of-the-art visual-inertial odometry (VIO) systems, however, are too computationally demanding for resource-constrained hardware, such as micro-drones and smart glasses. This work presents LEVIO, a fully featured VIO pipeline optimized for ultra-low-power compute platforms, allowing six-degrees-of-freedom (DoF) real-time sensing. LEVIO incorporates established VIO components such as Oriented FAST and Rotated BRIEF (ORB) feature tracking and bundle adjustment, while emphasizing a computationally efficient architecture with parallelization and low
memory usage to suit embedded microcontrollers and low-power systems-on-chip (SoCs). The paper proposes and details the algorithmic design choices and the hardware-software co-optimization approach, and presents real-time performance on resource-constrained hardware. LEVIO is validated on a parallel-processing ultra-low-power RISC-V SoC, achieving 20 FPS while consuming less than 100 mW, and benchmarked against public VIO
datasets, offering a compelling balance between efficiency and accuracy. To facilitate reproducibility and adoption, the complete implementation is released as open-source.
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All authors Jonas Kühne, Christian Vogt, Michele Magno, Luca Benini
Image and Video Processing · Cross-listed from physics.app-ph
Physics-Based Learning of the Wave Speed Landscape in Complex Media
Baptiste Hériard-Dubreuil, Emma Brenner, Benjamin Rio et al. (+4 more)
Wave velocity is a key parameter for imaging complex media, but in vivo measurements are typically limited to reflection geometries, where only backscattered waves from short-scale heterogeneities are accessible. As a result, conventional reflection imaging fails to recover large-scale variations of the wave velocity landscape. Here we show that
matrix imaging overcomes this limitation by exploiting the quality of wave focusing as an intrinsic guide
star. We model wave propagation as a trainable multi-layer network that leverages optimization and deep learning tools to infer the wave velocity distribution. We validate this approach through ultrasound experiments on tissue-mimicking phantoms and human breast tissues, demonstrating its potential for tumour detection and characterization. Our method is broadly applicable to any kind of waves and media for which a reflection
matrix can be measured.
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All authors Baptiste Hériard-Dubreuil, Emma Brenner, Benjamin Rio, William Lambert, Foucauld Chamming's, Mathias Fink, Alexandre Aubry
Systems and Control
Power Reserve Procurement Considering Dependent Random Variables with PCE
Nicola Ramseyer, Matthieu Jacobs and Mario Paolone
This paper presents an approach for the modelling of dependent random variables using generalised
polynomial chaos. This allows to write chance-constrained optimization problems with respect to a joint distribution modelling dependencies between different
stochastic inputs. Arbitrary dependencies are modelled by using Gaussian copulas to construct the joint distribution. The paper exploits the problem structure and develops suitable transformations to ensure tractability. The proposed method is applied to a probabilistic power reserve procurement problem. The effectiveness of the method to capture dependencies is shown by comparing the approach with a standard approach considering independent random variables.
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Image and Video Processing · Cross-listed from cs.CV
HypCBC: Domain-Invariant Hyperbolic Cross-Branch Consistency for Generalizable Medical Image Analysis
Francesco Di Salvo, Sebastian Doerrich, Jonas Alle et al. (+1 more)
Robust generalization beyond training distributions remains a critical challenge for deep neural networks. This is especially pronounced in medical image analysis, where data is often scarce and
covariate shifts arise from different hardware devices, imaging protocols, and heterogeneous patient populations. These factors collectively hinder reliable performance and slow down clinical adoption. Despite recent progress, existing learning paradigms primarily rely on the Euclidean
manifold, whose flat geometry fails to capture the complex, hierarchical structures present in clinical data. In this work, we exploit the advantages of
hyperbolic manifolds to model complex data characteristics. We present the first comprehensive validation of
hyperbolic representation learning for medical image analysis and demonstrate statistically significant gains across eleven in-distribution
datasets and three ViT models. We further propose an unsupervised, domain-invariant
hyperbolic cross-branch consistency constraint. Extensive experiments confirm that our proposed method promotes domain-invariant features and outperforms state-of-the-art Euclidean methods by an average of $+2.1\%$ AUC on three domain generalization
benchmarks: Fitzpatrick17k, Camelyon17-WILDS, and a cross-
dataset setup for retinal imaging. These
datasets span different imaging modalities, data sizes, and label granularities, confirming generalization capabilities across substantially different conditions. The code is available at https://github.com/francescodisalvo05/
hyperbolic-cross-branch-consistency .
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All authors Francesco Di Salvo, Sebastian Doerrich, Jonas Alle, Christian Ledig
Systems and Control
Impact of Physics-Informed Features on Neural Network Complexity for Li-ion Battery Voltage Prediction in Electric Vertical Takeoff and Landing Aircrafts
Eymen Ipek and Mario Hirz
The electrification of vertical takeoff and landing aircraft demands high-fidelity battery management systems capable of predicting voltage response under aggressive power dynamics. While data-driven models offer high accuracy, they often require complex architectures and extensive training data. Conversely, equivalent
circuit models (ECMs), such as the second-order model, offer physical interpretability but struggle with high C-rate non-linearities. This paper investigates the impact of integrating physics-based information into data-driven surrogate models. Specifically, we evaluate whether physics-informed features allow for the simplification of neural network architectures without compromising accuracy. Using the open-source electric vertical takeoff and landing (eVTOL) battery
dataset, we compare pure data-driven models against physics-informed data models. Results demonstrate that physics-informed models achieve comparable accuracy to complex pure data-driven models while using up to 75% fewer trainable parameters, significantly reducing computational overhead for potential on-board deployment.
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Systems and Control · Cross-listed from cs.DC
Joint Network-and-Server Congestion in Multi-Source Traffic Allocation: A Convex Formulation and Price-Based Decentralization (Extended Version)
Tamoghna Sarkar and Bhaskar Krishnamachari
This paper studies an important rate allocation problem that arises in many networked and distributed systems: steady-state traffic rate allocation from multiple sources to multiple service nodes when both (i) the access-path delay on each source-node route is rate-dependent (capacity-constrained) and convex, and (ii) each service node (also capacity-constrained) experiences a load-dependent queueing delay driven by aggregate load from all sources. We show that the resulting flow-weighted end-to-end delay minimization is a convex program, yielding a global system-optimal solution characterized by KKT conditions that equalize total marginal costs (a path marginal access term plus a node congestion price) across all utilized routes. This condition admits a Wardrop-type interpretation: for each source, all utilized options equalize total marginal cost, while any option with strictly larger total marginal cost receives no flow. Building on this structure, we develop a lightweight distributed pricing-based
algorithm in which each service node locally computes and broadcasts a scalar congestion price from its observed aggregate load, while each source updates its traffic split by solving a small separable convex allocation problem under the advertised prices. Numerical illustrations demonstrate convergence of the distributed iteration to the centralized optimum and highlight the trade-offs induced by jointly modeling access and service congestion.
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