Systems and Control · Cross-listed from math.OC
Predictor-Based Exponential Tracking of Turbulent Solutions for the Kuramoto–Sivashinsky Equation with Input Delay
Amadou Cissé
Uniform exponential tracking is addressed for nonstationary trajectories of the nonlinear Kuramoto–Sivashinsky equation subject to a constant input delay. The reference belongs to a family of complete trajectories contained in the global attractor and need not be stationary, periodic, slowly varying, or generated by a finite-dimensional exosystem. The delayed input is represented by a first-order transport equation coupled with the fourth-order tracking-error dynamics. A predictor–backstepping transformation compensates for the temporal mismatch between command generation and actuation by mapping the augmented closed-loop system into the nominal delay-free error dynamics driven by the outgoing trace of a homogeneous transport subsystem. This subsystem vanishes after one delay interval. Uniform attractor bounds permit the feedback parameters and stability constants to be selected independently of the initial time and the reference trajectory. Global well-posedness and uniform exponential stability are established in the augmented state space. Numerical results show that, for the considered configuration, uncompensated delayed feedback amplifies the tracking error, whereas predictor compensation restores sustained decay. Predictor-consistency, finite-time-extinction, and discretization-refinement diagnostics support the numerical implementation.
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Systems and Control
New VSC-HVDC interconnection between the Iberian Peninsula and Balearic Archipelago to enable energy transition
Javier Renedo, Silvia Sanz Verdugo, Antonio Cordón et al. (+4 more)
One of the challenges of the Spanish Transmission System Operator (TSO) is the decarbonisation of the Balearic Archipelago, by means of the integration of Renewable Energy Sources (RES) in the islands, as well as increasing the transmission capacity between the Iberian Peninsula and the Balearic Islands. Since the Balearic Archipelago is an island power system, the decarbonisation brings challenges related to power system stability and operation. A new High Voltage Direct Current (HVDC) interconnection between the Iberian Peninsula power system and the Balearic Islands power system is planned to facilitate the decarbonisation of the Balearic Archipelago (PEN-BAL2 Project). The HVDC link will be based on Voltage Source Converter (VSC) technology and will consist of a bipole of 2x200 MW, a DC voltage of +-250 kVdc and +100/-150 Mvar of reactive power capacity for each converter station. One converter station will be connected to a future El Fadrell 400 kV substation (Castellón, Valencia, Iberian Peninsula), while the other converter station will be connected to the existing San Martín 220 kV substation (Mallorca Island, Balearic Islands). The link will have HVDC submarine cables of 363 km (approx.).This paper will describe the challenges for energy transition in the Balearic Archipelago, technology enablers in general and PENBAL2 VSC-HVDC interconnection.
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All authors Javier Renedo, Silvia Sanz Verdugo, Antonio Cordón, Belén Segura, David Castañeda, Rosalía Rivas, Patricia Labra
Signal Processing
BER-Aware Joint Parameter Optimization of Rydberg Atomic Quantum Receivers
Akash Kumar Mandal and Ming Shen
Rydberg-atom
quantum receivers (RAQRs) offer highly sensitive RF reception, but their communication performance depends jointly on atomic response, optical transduction, receiver noise, bandwidth, and wireless-channel conditions. This paper develops a BER-aware communication-theoretic framework for superheterodyne RAQR-assisted wireless communication, linking four-level Rydberg-atom dynamics and coherent optical detection to multipath propagation and digital communication performance. Closed-form instantaneous and average SNR and BER expressions are derived for square Gray-coded $M$-QAM over correlated Rayleigh fading. The RAQR operating point is then jointly optimized over atomic, optical, RF, and
geometric parameters using analytical block-wise updates within a fixed-point procedure subject to physical and bandwidth constraints. Numerical results demonstrate substantial gains in low-power reception, bandwidth utilization, robustness to detuning, fading and delay spread, outage, and communication coverage compared with conventional, advanced, and fixed-point RAQR receivers. The results demonstrate that BER-aware joint optimization translates the intrinsic sensitivity of Rydberg-atom sensing into tangible communication-level gains.
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Systems and Control
Integrating Agentic Artificial Intelligence with High-Performance Computing for Grid Planning
Samim Konjicija and Slaven Peles
We present AgentiGrid, an agentic artificial intelligence (AI) framework that integrates large
language models (LLMs) intelligence and high-performance computing (HPC) to streamline and accelerate the multi-scenario power flow studies. AgentiGrid is an autonomous decision-making
agent that proposes parameter modifications, invokes analyses through HPC analysis toolkit ExaGO, interprets results, and determines subsequent actions. ExaGO provides multiple power flow applications that can perform deterministic,
stochastic and security constrained optimal power flow analyses. AgentiGrid provides backends to multiple LLMs (OpenAI, Anthropic, Ollama, and Ollama cloud) augmented with context specific and task specific
prompts. Key features include interactive mid-search steering, goal-type-aware post-search analysis, and concurrent variant exploration for power flow optimization. A Streamlit-based graphical launcher provides real-time visualization of iteration progress and generates reports in natural
language. AgentiGrid is capable of autonomously converging transmission constrained alternating current optimal power flow in under 20 iterations, with near-perfect reliability
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Systems and Control · Cross-listed from cs.IT
Deep Reinforcement Learning for Optimization of STAR-RIS Phase and Energy Splitting Coefficients in OTFS-NOMA Framework
Rais. J. Gachaba, Manobendu Sarker and Anirban Bhowal
This paper considers a downlink communication framework comprising a simultaneously transmitting and reflecting reconfigurable intelligent surface (
STAR-RIS)-aided by orthogonal time frequency space (OTFS) and non-orthogonal multiple access (NOMA) technologies. Further, delay-Doppler mobility in such frameworks renders classical alternating optimization impractical for per-coherence interval reconfiguration. To mitigate such issues, the
STAR-RIS phase-shift and energy-splitting design is formulated as a constrained, non-convex sum-rate maximization problem with closed-form maximum ratio transmission beamforming and fixed NOMA power allocation. To circumvent the per-interval re-optimization burden, a deep reinforcement learning (DRL) approach is adopted that maps observed channel realizations to
STAR-RIS configurations through a single forward pass. Specifically, Beta-Space Soft Actor-Critic (SAC-BSE), a maximum
entropy DRL
agent, is proposed. Simulation results, with two NOMA-multiplexed users on each
STAR-RIS branch, confirm rapid convergence, limit the sum-rate degradation to roughly 10% across a 128-fold user-speed range, and yield consistent gains over OTFS-only, NOMA-only,
STAR-RIS-only, fixed-split, and mode-switching baselines as transmit power and the number of
STAR-RIS elements increase.
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Audio and Speech Processing
Discriminative Flow Matching: Beyond Time-Conditioning in Generative Restoration via Flow-State Representations
Shrishti Saha Shetu, Emanuël A. P. Habets and Andreas Brendel
Existing Conditional Flow Matching (CFM) formulations describe transport progress using an explicit interpolation coordinate, commonly interpreted as time, assuming that a single global variable adequately represents a sample's position along the generative trajectory. In restoration tasks, however, transport progress is sample-dependent because the initial distribution may exhibit varying statistical dependencies with the target distribution. Thus, samples at the same interpolation coordinate can differ substantially in degradation level, distance to the target distribution, and restoration difficulty. We investigate whether signal representations learned by discriminatively trained models provide a meaningful description of generative transport state in CFM-based restoration. Through systematic latent-space analysis, we show that discriminative representations organize according to degradation severity and follow a consistent trajectory toward the clean-data
manifold during generation. Motivated by these observations, we introduce the Discriminative Flow-State Hypothesis, which posits that discriminative representations encode a transport state governing generative restoration. Based on this hypothesis, we propose Discriminative Flow Matching, which conditions the Flow-Matching velocity field on Discriminative Flow-State Representations rather than explicit time coordinates. Experiments on
speech enhancement and image denoising show that these representations characterize restoration progress, enable adaptive inference, and consistently outperform CFM and
diffusion-related baselines. Our findings suggest that discriminative representations provide an effective state-aware alternative to explicit time conditioning and offer a novel perspective on the relationship between discriminative and CFM-based generative modeling.
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Image and Video Processing
Explainable Multimodal Deep Learning Integrating Imaging and Clinical Data for Oral Potentially Malignant Disorder Detection
Ruilin You, Yihan Wang, Jiabin Chen et al. (+4 more)
Oral potentially malignant disorders (OPMDs) are critical precursors to oral cancer, yet clinical detection remains challenging because of substantial phenotypic heterogeneity and overlap with benign conditions. Although image-based deep learning shows promise for automated screening, visual information alone may be insufficient in real-world settings, where diagnostic decisions also rely on patient-specific risk factors. We developed M2-OPMDNet, a
multimodal deep learning framework that integrates co-registered white-light and autofluorescence intraoral images with structured clinical information for OPMD detection. A customized questionnaire was designed to capture clinically relevant risk factors and symptoms in a standardized, reproducible format for integration with image-derived features. Multiple image encoders, including conventional convolutional neural networks and foundation model-based architectures, were evaluated using a prospectively collected
dataset reflecting real-world screening conditions. Model interpretability was assessed using SHapley Additive exPlanations (SHAP) to quantify feature- and modality-level contributions. M2-OPMDNet achieved an AUC of 0.952, outperforming unimodal approaches and showing improved performance for visually subtle lesions. SHAP analysis demonstrated that structured clinical variables contributed substantially to risk estimation and complemented imaging features. These results demonstrate that explainable
multimodal learning combining white-light and autofluorescence imaging with structured clinical data can provide accurate, transparent, and clinically grounded OPMD detection. M2-OPMDNet offers a scalable framework for real-world oral cancer screening and decision support.
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All authors Ruilin You, Yihan Wang, Jiabin Chen, Cherie Wink, Petra Wilder-Smith, Rongguang Liang, Bofan Song
Image and Video Processing
Fractional-Order Adaptive Motion Magnification: Phase-Reliability Weighting for Noise-Constrained Video Amplification
Alejandro Garnung Menéndez
Eulerian
video amplification boosts sub-pixel motion by band-pass filtering per-pixel intensity traces and applying a uniform gain. That gain ignores local structure, so sensor noise is amplified together with the signal, especially in textureless regions where the monogenic phase is unreliable. We propose FrAM (Fractional-order Adaptive Motion Magnification), a pipeline developed first offline and then as a causal stream. It replaces the constant temporal gain with a Grünwald–Letnikov derivative of fractional order, giving continuous control over high-frequency emphasis, and replaces the uniform spatial gain with a per-pixel weight derived from the local amplitude of the monogenic signal. On a controlled synthetic sequence split into textured and flat halves, FrAM matches the amplification of the Eulerian baseline while keeping flat-region temporal noise at the input level. The reduction holds across an eightfold range of input noise levels. Real
videos show improved spatial selectivity and lower background noise in every case. The causal reformulation cuts the per-frame cost by two orders of magnitude, reaching 69\,fps at 640$\times$480.
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Systems and Control
Estimating the Health and State of Charge of Each Cell in a Second-Life Battery System from Field Data
Martin Cornejo, Julian Meyer-Schwickerath, Juan Victor Sandalinas et al. (+1 more)
Effective use of battery storage depends on reliable estimation of its state of health (SOH) and state of charge (SOC). Model-based state estimation requires the open-
circuit voltage (OCV) curve, which is typically unknown for second-life batteries. We present a framework that jointly estimates the states and parameters of an equivalent
circuit model solely from field operation data, using Gaussian process regression to reconstruct the OCV curve. Applied to a real second-life battery system of 27 modules and 324
cells, it reveals SOH heterogeneity, a systematic SOC imbalance, and two faulty
cells, all validated against a reference measurement. We aggregate the
cell SOH and SOC to module level and
benchmark them against a lumped-module model fitted without the individual
cell voltages. The lumped-module model follows the average behavior and cannot capture the limiting
cells, overestimating SOH by up to 31% and SOC by up to 23%.
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All authors Martin Cornejo, Julian Meyer-Schwickerath, Juan Victor Sandalinas, Andreas Jossen
Audio and Speech Processing
Brain2Speech-Net: Fast and Intelligible Brain-to-Speech Synthesis Without Text Decoding
Shreeram Suresh Chandra, Zexin Cai, Yu Tsao et al. (+2 more)
The loss of
speech limits communication for individuals with paralysis. Direct neural-to-
speech synthesis is challenging due to the limited availability of neural data for training
speech brain-computer interfaces. Most existing systems rely on cascaded neural-to-text-to-
speech pipelines, which increase inference latency and propagate errors across stages. We present
Brain2
Speech-Net, a single-stage neural-to-
speech generation framework without intermediate text decoding. We use a differentiable phoneme bottleneck and a deep-HMM
alignment mechanism to map long neural recordings into the latent space of a text-to-
speech (TTS) model, enabling high-quality
speech synthesis.
Brain2
Speech-Net is the only system in our comparison that produces intelligible
speech while generating faster than real time.
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All authors Shreeram Suresh Chandra, Zexin Cai, Yu Tsao, Simon King, Berrak Sisman
Signal Processing
Opportunistic Data Offloading for Robotic Operations in Dynamically Varying Channel Environments
Heeirthan Shanthan, Winston Hurst and Yasamin Mostofi
This paper studies energy-efficient operation of autonomous vehicles (AVs) in dynamic environments with moving obstacles and while communicating over mmWave channels. The obstacles induce severe attenuation of the mmWave channel resulting in a highly dynamic communication environment. In this setting, we consider the problem of jointly optimizing motion and communication energy for an AV that safely navigates among dynamic obstacles toward a designated destination while ensuring timely transmission of onboard sensing or telemetry data over mmWave channels. We then seek a real-time methodology to compute energy-efficient trajectories in a setting where dynamic obstacles induce both safety constraints and time-varying mmWave blockage, leading to tightly coupled motion-communication trade-offs. We propose a nonlinear model predictive control (NMPC) framework that enables anticipative communication and motion decision-making and energy co-optimization, augmented with a control barrier function (CBF) to ensure safety. Extensive simulation results demonstrate the effectiveness of our approach, reducing total energy consumption by up to 37.3% compared to baseline strategies. Overall, our results demonstrate that the proposed NMPC-based framework significantly enhances energy efficiency and performance of AVs under dynamic, blockage-sensitive mmWave communication constraints.
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Systems and Control · Cross-listed from cs.NI
Waves on the Walls: Empirical Characterization of mmWave Lateral Waves for Enhanced Indoor Coverage
Apala Pramanik, Avhishek Biswas, Sasitharan Balasubramaniam et al. (+2 more)
High-frequency millimeter-wave (mmWave) communication systems are constrained by the surrounding environment, where walls are traditionally treated as obstacles that block or reflect signals indoors. Consequently, current beamforming strategies are tailored to circumvent these obstructions. In this paper, a paradigm shift is introduced that leverages lateral wave propagation along building interfaces to extend mmWave coverage. Unlike traditional reflections, lateral waves travel along the boundary between two media of different refractive indices and decay algebraically with distance, offering a potential alternative path for mmWave connectivity. While well-established at low frequencies in natural media, the existence of lateral waves at mmWave frequencies along engineered building materials has not been demonstrated before. To this end, the first experimental characterization of mmWave lateral waves along a wall is reported. Extensive controlled measurements are employed to characterize the signal-grazing geometry and to establish a frequency and distance-dependent path-loss model for this phenomenon. The results provide the first empirical foundation for a new class of interface-guided mmWave links.
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All authors Apala Pramanik, Avhishek Biswas, Sasitharan Balasubramaniam, Christos Argyropoulos, Mehmet C. Vuran
Signal Processing · Cross-listed from cs.NI
Network Availability Enhancement in Low-Altitude HetNets: A Cross-Layer Design Perspective
Teng Wu, Jiandong Li, Junyu Liu et al. (+4 more)
This paper proposes a computing-communication resource interchange method to enhance network availability (NA) in low-altitude heterogeneous networks (LA-HetNets). In these networks, communication resource conflicts and imbalances, caused by extreme heterogeneity (diverse mobility, mixed delays, and hybrid transmission), and cross-regional traffic, reduce reliability and lead to unavailability. Restoring NA requires additional communication resources, yet dynamic cross-regional scheduling is limited, making locally redundant computing resources an alternative to reduce communication resource overhead. While computing resources address medium access control (MAC)-layer unreliability, physical (PHY)-layer functionalities still rely on communication resources. Thus, it remains unclear whether increasing computing resources alone can achieve target NA, especially under greater heterogeneity. We elaborate on the impact of heterogeneity on NA and show that expanding computing resources alone cannot meet target NA under high heterogeneity, as NA degrades sharply due to increased communication capability demands. To overcome this, we propose a cross-layer optimization method enabling computing-communication resource interchange to address both MAC- and PHY-layer unreliability. By reducing processing delays with computing resources while ensuring MAC-layer reliability, our method extends PHY-layer transmission delay and expands communication resources. Simulations demonstrate our approach's superiority in achieving target NA under greater heterogeneity, revealing that computing-communication resource interchange fulfills expanding communication capability demands more effectively than conventional resource overhead reduction.
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All authors Teng Wu, Jiandong Li, Junyu Liu, Min Sheng, Mohammadali Mohammadi, Hien Quoc Ngo, Michail Matthaiou
Systems and Control
Grid-Mode-Aware Model Predictive Control of Hybrid Energy Storage Systems for AI Data Center Power Smoothing
Xin Chen
To facilitate the grid-friendly integration of highly variable AI data center loads, this paper proposes a grid-mode-aware model predictive control (G-MPC) framework for managing a hybrid energy storage system (HESS) to smooth grid-side power demand. The framework optimally coordinates a battery energy storage system (BESS) and a supercapacitor (SC) by solving a multi-step optimization problem in a receding-horizon manner. In particular, band-pass filter dynamics are directly embedded in the G-MPC formulation to extract and suppress grid-side power components associated with vulnerable grid oscillatory modes, thus mitigating load-induced grid oscillations. The resulting G-MPC optimization jointly minimizes violations of grid-side power-envelope, ramp-rate, and modal-power requirements and the degradation and power-ramping costs of the BESS and SC, while satisfying power limits, state-of-charge limits, and other operational constraints. To enable real-time implementation, a fix-and-re-optimize
algorithm is developed to solve each G-MPC problem efficiently while preventing simultaneous charging and discharging. Extensive simulations demonstrate the effectiveness, flexibility, and computational efficiency of the proposed framework. The results also highlight the importance of explicitly suppressing power components associated with vulnerable grid modes, rather than merely reducing overall load variations, to effectively mitigate grid oscillations.
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Image and Video Processing
Development and Evaluation of Ultrasound Image Learning Pipelines for MASLD Risk Stratification
Guangyi Zhang, Xiaohong Wang, Eugene Cheah et al. (+4 more)
Metabolic dysfunction-associated steatotic liver disease (MASLD) affects approximately 30% of the general population. Ultrasound-based imaging, including B-mode imaging and shear wave elastography (SWE), is widely used for noninvasive fibrosis assessment; however, the role of deep learning-based ultrasound image learning for MASLD risk stratification remains insufficiently characterized. In this study, we developed and evaluated ultrasound image learning pipelines using B-mode and SWE images for fibrosis staging and identification of patients with at-risk metabolic dysfunction-associated steatohepatitis (MASH). A total of 250 ultrasound examinations, one exam per subject, were included. Model performance was evaluated using 3-fold cross-validation with area under the receiver operating characteristic curve (AUROC). End-to-end SWE image learning achieved performance comparable to operator-guided SWE across fibrosis stages. Overall, SWE-based learning consistently outperformed B-mode image learning in fibrosis staging, with AUROC improvements from 0.64 (95%CI: [0.56, 0.72]) to 0.72 (95% CI: [0.65, 0.79]) for F>=2 (significant fibrosis, p=0.11), from 0.67 (95%CI: [0.58, 0.75]) to 0.78 (95% CI:[0.72, 0.85]) for F>=3 (advanced fibrosis, p=0.02), and from 0.69 (95%CI: [0.56, 0.82]) to 0.80 (95%CI: [0.72, 0.89]) for F4 (cirrhosis, p=0.10). These findings highlight the potential of SWE image learning for MASLD risk stratification.
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All authors Guangyi Zhang, Xiaohong Wang, Eugene Cheah, Peng Guo, Brian A. Telfer, Theodore T. Pierce, Anthony E. Samir
Image and Video Processing
Ultrasound-Based Prediction of Cirrhosis Decompensation Using Large-Scale Computer Vision Models
Guangyi Zhang, Peiyun Ni, Eugene Cheah et al. (+4 more)
Decompensation represents a critical transition in the course of cirrhosis, yet clinicians have limited non-invasive tools to reliably predict its onset. In this study, we propose a novel imaging-based approach that leverages large-scale computer
vision models to analyze routine abdominal ultrasound images and extract predictive features beyond those captured by traditional laboratory-based risk scores. Ultrasound is widely available, low cost, and suitable for longitudinal surveillance, making it an attractive modality for scalable risk stratification and long-term follow-up. Our framework integrates automated ultrasound data processing with modern deep learning architectures to identify patients at high risk of decompensation prior to the occurrence of clinical deterioration. This non-invasive strategy offers a practical complement to existing clinical scoring systems and may enable earlier, more proactive management of patients with compensated cirrhosis.
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All authors Guangyi Zhang, Peiyun Ni, Eugene Cheah, Rajat Chandra, Peng Guo, Raymond T. Chung, Anthony E. Samir
Systems and Control · Cross-listed from cs.RO
Scalable Edge-assisted Fusion and Path Prediction for Connected Autonomous Vehicles
Tyler Landle, Jackson Isenberg, Abhijit Chatterjee et al. (+2 more)
The planning
algorithms inside an Autonomous Vehicle (AV) rely on information from on-board sensors whose line of sight is limited by emerging traffic conditions and occlusions. Edge-assisted creation of a unified world model fusing information from AVs and Road Side Units (RSUs) in a geographical locale, and the prediction of AVs' future trajectories, can enhance the planning
algorithms inside AVs to improve quality metrics, such as better traffic flow and collision prevention. AVs participating in such enhancements are called Connected Autonomous Vehicles (CAVs). However, such information generated by the edge (world model and motion predictions) must reach the planners within a tight Age of Information (AoI) time budget to be useful. The state of the art fuses per-CAV information: each AV fuses inputs from other actors locally, which limits both scalability with actor count and quality of results. We present Conductor, an edge-based solution for creating a unified world model from the perspective of a fixed anchor (e.g., an RSU) in a locale and predicting future trajectories of AVs in that locale. Our solution adheres to the AoI time budget by dynamically limiting the number of AVs that would lead to the best quality of results. Specifically, we introduce an occlusion-aware selector that favors information contribution by AVs that detect objects in the locale not covered by RSUs. We pair this selector with a runtime controller that adapts both the number of AV inputs to fuse and the amount of trajectory predictions in each cycle to stay within the AoI time budget. Evaluation on CAV simulation infrastructure shows our joint selector-controller meets the AoI safety bound across traffic scenarios with up to 31 CAVs, with fusion fidelity close to an Oracle and much better than a random selector under the same AoI constraint.
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All authors Tyler Landle, Jackson Isenberg, Abhijit Chatterjee, Alexandros Daglis, Umakishore Ramachandran
Image and Video Processing
Cross-modal triage network: a multimodal deep learning framework for severity-based triage and visual explainability in chest radiographs
Zinah Ghulam, Richa Mittal and Eranga Ukwatta
Purpose: Increased number of chest radiograph (CXR) scans create a triage bottleneck, queueing urgent examinations behind routine ones. Existing AI tools are predominantly unimodal binary classifiers lacking severity awareness, and
multimodal systems are rarely benchmarked against expert radiologists. To this end, we developed a
multimodal deep learning framework for joint severity triage, pathology detection, and native visual explanation. Approach: We propose the cross-modal triage network (CMTN), fusing a Swin
Transformer V2 visual encoder with a PubMedBERT text encoder via gated cross-
attention. The CMTN was trained on 34,639 image-text pairs (12,489 patients) from MIMIC-CXR-JPG, optimizing an ordinal focal loss for four-tier severity triage and binary cross-
entropy for 14 pathologies. Beyond quantitative benchmarking,
attention heatmaps were evaluated against a blinded expert radiologist in a two-phase clinical audit comparing model triage output to expert severity assessment (100 cases) and grading spatial-semantic concordance (116 heatmaps). Results: The CMTN achieved strong ordinal agreement with reference labels (quadratic weighted kappa [QWK] = 0.9341, 95% CI: 0.9219 to 0.9449) and macro-AUROC of 0.9970 across 14 pathologies, with 34~ms latency, outperforming the state-of-the-art BioViL
multimodal baseline (QWK = 0.7679). However, the blinded Phase I clinical audit revealed substantially lower agreement with genuine radiologist judgment (QWK = 0.1399). Phase II found 54.3% of heatmaps achieved clinically acceptable spatial localization. Conclusions: The CMTN demonstrated an efficient
multimodal architecture for CXR triage. The divergence between algorithmic and radiologist agreement demonstrates that
benchmark performance against NLP-derived labels is insufficient, highlighting the need for radiologist-labeled ground truth before clinical deployment.
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Systems and Control
A Constraint-Aware Generative Framework for Synthetic Origin-Destination Demand in Logistics Networks
Leian Chen
Large-scale logistics networks require synthetic data generation capabilities to support scenario-based planning under novel conditions-such as network reconfiguration and demand shocks. Existing approaches, which rely primarily on historical observations, lack the ability to generate demand patterns that adapt to changes in network
topology while respecting operational constraints. We propose a constraint-aware conditional generative framework for synthetic origin-destination demand generation in hierarchical logistics networks. The framework models demand as a conditional distribution over destinations given each origin, enabling
topology-aware synthesis that is both topologically realistic and operationally feasible. Operational guidance is incorporated directly into the generative objective via differentiable constraints, while a flexible conditioning mechanism supports various operational contexts and adaptation to evolving network configurations. We instantiate the proposed framework based on a conditional generative model. Experimental validation on industrial real fulfillment and transportation network demonstrates 16% improvement over graph neural network baselines, 87% operational compliance, and efficient cold-start adaptation, enabling applications in capacity planning, network design evaluation, and routing optimization.
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Systems and Control · Cross-listed from cs.LG
Data-Driven Learning of Unknown Nonlinear Differential Equations Using Functional Analysis
Seyyed Shaho Alaviani, Yongzhi Qu and Gregory W. Vogl
In this paper, the problem of data-driven discovery of nonlinear ordinary differential equations (ODEs) is recast, and a new interpretable machine learning (ML) method is proposed. The proposed method aims to learn the unknown vector field of nonlinear dynamics without prior knowledge of the system's physics from only one single state trajectory's data. The proposed method has two fundamental differences with existing methods: 1) the formulation presented in this method is derived based on Functional Analysis and Operator Theory, and 2) the cost function is constructed in the function space as a distance between two functions as an integral, instead of the discrete-sum of errors used in existing ML approaches. An incremental learning
algorithm is proposed to learn the unknown vector field to handle new training samples in an online manner. The proposed method can discover the unknown vector field from both forced and unforced autonomous and non-autonomous (or time-varying) dynamical systems. The proposed method is able to simultaneously discover unknown external forces as a function of time and unknown underlying dynamics. Finally, numerical examples are given to demonstrate the advantages of the proposed method.
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Audio and Speech Processing · Cross-listed from cs.SD
Scalable Context Orchestration for Serving LLMs Over Voice
Linyi Jiang, Silvery D. Fu and Yifei Zhu
Voice AI applications are gaining popularity as advances in large
language models (LLMs) enable more natural and accessible spoken interactions. Serving these applications requires accounting not only for what users say, but also for how they speak (e.g., speaking rate) and the conditions under which their audio is captured and transmitted (e.g., background noise and packet loss). However, existing LLM systems represent conversation context as a flat, growing sequence of messages, leaving voice-specific context implicit in the audio. As a result, they can generate responses that are poorly aligned with user preferences, degrade interaction quality under adverse environmental conditions, and incur high costs over long voice sessions. We present llmovoice, a context-management middleware that explicitly models voice context and orchestrates its use. At each turn, llmovoice constructs a bounded voice context from the current user input, relevant interaction history, and explicit paralinguistic and environmental states. It then uses the serving LLM to reason over this context and generate runtime directives that guide how the system responds. We evaluate llmovoice on real-world voice applications and
benchmarks. It reduces speaking-rate
alignment error by 52.4%, lowers the false-interruption rate from 46.0% to 0.9% under packet loss, and reduces model usage cost by 79.2%. For long sessions, llmovoice reduces per-turn cost by up to 24.9 times while retaining up to 98.7% of baseline answer quality.
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Systems and Control
Formation Matrix and Energy-based Control of Multi-Agent Systems
Martín Crespo, Sergio Junco and Matías Nacusse
This paper presents an energy-based controller for a multiagent robotic system designed to achieve and maintain a specific formation while moving on a plane and avoiding collisions between
agents. The controller emulates a network of elementary spring-damper modules connecting pairs of
agents. This network, with its de-energized states representing the desired formation, determines the system's dynamics, which is fully encapsulated by a bond graph model. The modeling is further enhanced through the introduction of a formation
matrix, using a graph-theoretic approach, that describes both the distances and relative velocities among the
agents of the arrangement. This
matrix mathematically represents the interconnection and energy-exchange structure of the bond graph, allowing us to put it in correspondence with the control-by-interconnection CbI-scheme of the IDA-PBC theory, facilitating the solution of the formation control problem within the port-
Hamiltonian system framework. Furthermore, the paper presents leader-following and position-based formation control systems based on the CbI scheme, including a stability analysis of the corresponding closed-loop systems. The theoretical findings are validated through numerical simulations across various scenarios.
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Audio and Speech Processing
Deep Neural Compression for RIR-Characterized Acoustic Environments with Structure-Aware Constraints
Chen-Yuan Ning, Yang Ai, Hui-Peng Du et al. (+2 more)
Room impulse responses (RIRs) characterize the acoustic environment of a room by capturing how sound propagates and decays within an enclosed space. In applications such as immersive audio rendering, accurate acoustic reconstruction often relies on spatially densely sampled RIRs. This consequently gives rise to a large volume of RIR data, imposing a substantial burden on storage. Although recent neural audio codecs provide an effective framework for low-bitrate compression, their training objectives are mainly tailored to
speech and general audio, and are therefore not well aligned with the acoustic characteristics of RIRs. Therefore, we propose an EnCodec-based neural RIR compression method, which incorporates RIR structure-aware constraints at two levels. Specifically, at the RIR level, structure-aware constraints are imposed on the global decay behavior and local energy distribution of RIRs through energy decay curve (EDC) regularization and a short-time window energy constraint, while at the reverberant-
speech level, reverberant-
speech supervision is further introduced to constrain the consistency of the reverberant
speech generated by the reconstructed RIRs. Experimental results show that, at a low bitrate of 375 bps, the proposed method achieves lower RIR reconstruction error and better reverberant-
speech perceptual consistency than audio-oriented codecs.
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All authors Chen-Yuan Ning, Yang Ai, Hui-Peng Du, Xiao-Hang Jiang, Zhen-Hua Ling
Systems and Control · Cross-listed from math.OC
Transversality Conditions for Boundary Constraints Defined by Differential Equations
Isaac M Ross
What are the transversality conditions for an optimal control problem when the boundary conditions are defined by differential equations? This seemingly bizarre question is motivated by trajectory optimization problems in the $N$-body system. The question, however, is more fundamental and goes beyond problems in astrodynamics to nonintegrable dynamical systems in general. The main contribution of this paper is the development of generic initial- and final-time transversality conditions for optimal control problems whose boundary conditions are defined in terms of differential equations with side conditions. The mathematical definition of differential boundary conditions are part of the foundations developed in this paper. To support the new fundamentals, the concept of coordinated/uncoordinated clock times and weak adjoint covectors are introduced. In the case of uncoordinated clock times, the new transversality conditions reveal that there exists a special situation where a weak adjoint covector is orthogonal to the vector field of the boundary differential equation. This condition is sharply different from the classical statement of orthogonality with respect to the endpoint
manifold. The
theorems developed in this paper are generic. An application of the
theorems to several cases in the three-body problem are described in separate papers.
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Signal Processing
THz-SynC: Collective Synthesis with Contextual-Bandit-Assisted Coordination for Reconfigurable Hybrid Optical-THz AI Datacenters
Jingting Jiang and Chong Han
Terahertz (THz) wireless interconnects offer high-capacity, low-latency, and energy-efficient rack-to-rack links capable of on-demand connectivity reconfiguration, serving as a promising complement to optical fabrics for communication-intensive distributed AI training datacenters. However, co-optimizing optical and THz resources to minimize collective completion time and transmission energy remains challenging due to dynamic optical congestion, THz channel fluctuations, and heterogeneous compute stragglers. Existing reconfigurable data-center designs predominantly optimize network
topology and traffic routing, with limited consideration of collective communication semantics in distributed AI workloads over hybrid fabrics. To address these challenges, we propose THz-SynC, a novel framework that integrates collective synthesis with contextual-bandit-assisted hybrid-fabric coordination to optimize the tradeoff between collective completion time and transmission energy. By exploiting collective-specific semantics, THz-SynC synthesizes tailored communication
topologies for All-to-All and AllReduce patterns while dynamically allocating THz resources. Furthermore, a contextual-bandit coordinator adaptively routes communication chunks across optical and THz links and selects rack power budgets leveraging real-time observations of network states and collective semantics. Trace-driven evaluations show that THz-SynC outperforms wired-only, wireless-only, and hybrid baselines, achieving a superior delay-energy Pareto frontier under dynamic network conditions.
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