Signal Processing
An Edge-Cloud Collaborative Architecture for Proactive Elderly Care: Real-Time Risk Assessment and Three-Level Emergency Response
Lijie Zhou and Luran Wang
The rapid aging of global populations has created an urgent need for intelligent healthcare monitoring systems to ensure the safety of elderly individuals living independently. Existing cloud-centric platforms face critical limitations, including high latency unsuitable for emergency response,
privacy risks from continuous transmission of sensitive data, and limited, single-channel alert mechanisms lacking scalability and context awareness. This paper proposes an edge-cloud collaborative architecture that addresses these challenges through real-time multi-modal sensor fusion, a four-dimensional risk assessment model, and a three-level emergency response system. The framework adopts a five-layer design - device, edge, service, data, and application layers - enabling real-time risk evaluation with end-to-end alert latency under three seconds. At the edge, a weighted multi-modal fusion
algorithm integrates data from five sensor types with confidence propagation. A unified risk score is generated by combining fall probability, physiological indicators, behavioral patterns, and sensor anomaly metrics. Based on dynamic thresholds, a three-tier notification system coordinates responses among family members, community doctors, and nearby volunteers. Experiments on CASAS, MIMIC-III, and SisFall
datasets show that the approach achieves 91% activity recognition accuracy and an 84% anomaly detection F1-score, outperforming single-sensor methods. Deployment on Raspberry Pi 4 gateways demonstrates sub-100 ms inference latency while preserving
privacy by keeping raw data local. This architecture advances practical,
privacy-preserving, and responsive elderly care systems.
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Signal Processing
Smartphone-Based Identification of Unknown Liquids via Active Vibration Sensing
Yongzhi Huang
Traditional
liquid identification instruments are often unavailable to the general public. This paper shows the feasibility of identifying unknown
liquids with commercial lightweight devices, such as a smartphone. The key insight is that different
liquid molecules have different viscosity coefficients and therefore must overcome different energy barriers during relative motion. With this intuition in mind, we introduce a novel model that measures
liquids' viscosity based on active vibration. However, building a robust system using built-in smartphone accelerometers is challenging. Practical issues include under-sampling, self-interference, and the impact of
liquid-volume changes. Instead of machine learning, we tackle these issues through multiple signal processing stages to reconstruct the original signals and cancel out the interference. Our approach estimates
liquid viscosity with a mean relative error of 2.9% and distinguishes 30 types of
liquids with an average accuracy of 95.47%.
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Audio and Speech Processing · Cross-listed from cs.SD
Sommelier: Scalable Open Multi-turn Audio Pre-processing for Full-duplex Speech Language Models
Kyudan Jung, Jihwan Kim, Soyoon Kim et al. (+3 more)
As the paradigm of AI shifts from text-based LLMs to
Speech Language Models (SLMs), there is a growing demand for full-duplex systems capable of real-time, natural human-computer interaction. However, the development of such models is constrained by the scarcity of high-quality, multi-speaker conversational data, as existing large-scale resources are predominantly single-speaker or limited in volume. Addressing the complex dynamics of natural dialogue, such as overlapping and back-channeling remains a challenge, with standard processing pipelines suffering from diarization errors and ASR
hallucinations. To bridge this gap, we present a robust and scalable open-source data processing pipeline designed for full-duplex model.
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All authors Kyudan Jung, Jihwan Kim, Soyoon Kim, Jeonghoon Kim, Jaegul Choo, Cheonbok Park
Systems and Control
Online Feedback Optimization of Energy Storage to Smooth Data Center Grid Impacts
Yanyong Mao, Johanna L. Mathieu and Vladimir Dvorkin
The growing electricity demand of AI data centers introduces significant voltage variability in power networks, affecting not only their own operation but also the experience of all users sharing the network. To smooth data center impacts on power networks, we develop an online feedback optimization approach that controls distributed battery energy storage systems to mitigate voltage issues induced by data center operations. The controller adjusts the active and reactive power setpoints of distributed battery systems in response to voltage measurements, with a two-fold objective: managing voltage to minimize the magnitude of constraint violations and smoothing voltage profiles. Control performance is evaluated in a high-fidelity simulation environment that integrates a three-phase distribution feeder and a detailed battery system model, and benchmarked against a local control approach with similar objectives but without optimality guarantees and constraint enforcement. We show that the proposed controller delivers consistent voltage regulation in the long term, while the local control approach pursues the objectives more aggressively but quickly hits the storage limits.
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Systems and Control
Sustainable Load Balancing for Wireless Networks With Renewable Energy Sources
Mustafa Mohammed Hasan Alkalsh, Adam Samorzewski and Adrian Kliks
Future wireless networks powered by renewable energy sources and storage systems (e.g., batteries) require energy-aware mechanisms to ensure stability in critical and high-demand scenarios. These include large-scale user gatherings, especially during evening hours when
solar generation is unavailable, and days with poor wind conditions that limit the effectiveness of wind-based energy harvesting. Maintaining network performance under such constraints, while preserving stored energy, remains a key challenge. This work proposes an enhanced Proactive-Reactive Load Balancing
algorithm that integrates energy conditions into mobility management. By leveraging standardized mobility events, the
algorithm optimizes traffic distribution and energy utilization (avoiding complete drainage of stored energy), thereby preventing service degradation. Simulations show improved energy sustainability and network performance under congestion and limited
solar availability.
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Systems and Control
Performance Guarantees for Data-Driven Sequential Decision-Making
Bowen Li, Edwin K. P. Chong and Ali Pezeshki
The solutions to many sequential decision-making problems are characterized by dynamic programming and Bellman's principle of optimality. However, due to the inherent complexity of solving Bellman's equation exactly, there has been significant interest in developing various approximate dynamic programming (ADP) schemes to obtain near-optimal solutions. A fundamental question that arises is: how close are the objective values produced by ADP schemes relative to the true optimal objective values? In this paper, we develop a general framework that provides performance guarantees for ADP schemes in the form of ratio bounds. Specifically, we show that the objective value under an ADP scheme is at least a computable fraction of the optimal value. We further demonstrate the applicability of our theoretical framework through several applications: data-driven
robot path planning, pendulum stabilization, and multi-
agent sensor coverage.
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Systems and Control · Cross-listed from cs.RO
High-Speed, All-Terrain Autonomy: Ensuring Safety at the Limits of Mobility
James R. Baxter, Bogdan I. Epureanu, Paramsothy Jayakumar et al. (+1 more)
A novel local trajectory planner, capable of controlling an autonomous off-road vehicle on rugged terrain at high-speed is presented. Autonomous vehicles are currently unable to safely operate off-road at high-speed, as current approaches either fail to predict and mitigate rollovers induced by rough terrain or are not real-time feasible. To address this challenge, a novel model predictive control (MPC) formulation is developed for local trajectory planning. A new dynamics model for off-road vehicles on rough, non-planar terrain is derived and used for prediction. Extreme mobility, including tire liftoff without rollover, is safely enabled through a new energy-based constraint. The formulation is analytically shown to mitigate rollover types ignored by many state-of-the-art methods, and real-time feasibility is achieved through parallelized GPGPU computation. The planner's ability to provide safe, extreme trajectories is studied through both simulated trials and full-scale physical experiments. The results demonstrate fewer rollovers and more successes compared to a state-of-the-art baseline across several challenging scenarios that push the vehicle to its mobility limits.
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All authors James R. Baxter, Bogdan I. Epureanu, Paramsothy Jayakumar, Tulga Ersal
Systems and Control
A Control Architecture for Fast Frequency Regulation with Increasing Penetration of Inverter Based Resources (Extended Version)
Jose A. Solano-Castellanos, Hassan Haes Alhelou, Ali T. Al-Awami et al. (+2 more)
This paper addresses frequency regulation under operational constraints in interconnected power systems with high penetration of inverter-based renewable generation. A two-layer control architecture is proposed that combines optimized droop and Virtual Synchronous Machine (VSM) primary control with a Model Predictive Control (MPC) secondary layer operating at realistic control-room update rates. Unlike recently proposed approaches, the proposed framework integrates MPC within existing grid control structures, enabling constraint-aware coordination. A reduced-order frequency response model is systematically derived from a detailed grid model using Hankel singular values, and a reduced-order Kalman-Bucy observer enables state and disturbance estimation using only measurable outputs. Evaluation using representative data from the Kingdom of Saudi Arabia demonstrates effective frequency regulation under realistic operating conditions.
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All authors Jose A. Solano-Castellanos, Hassan Haes Alhelou, Ali T. Al-Awami, Mohannad Alkhraijah, Anuradha M. Annaswamy
Signal Processing
Realization of a Fully Connected Neural Layer Over-the-Air through Multi-hop Amplify-and-Forward Relays
Tolga Girici, Meng Hua and Deniz Gündüz
We study the problem of implementing a fully-connected layer of a neural network using wireless over-the-air computing. We assume a multi hop system with a multi-
antenna transmitter and receiver, along with a number of multi-hop amplify-and-forward relay devices in between. We formulate an optimization problem that optimizes the transmitter precoder, receiver combiner and amplify-and-forward gains, subject to relay device power constraint and transmitter power constraint. We propose an alternating optimization framework that optimizes the imitation accuracy. Simulation study results reveal that multi-hop relaying achieves an almost perfect classification accuracy when used in a neural network.
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Signal Processing · Cross-listed from q-bio.NC
Transcranial Alternating Current Stimulation (tACS) for patients with Post-Stroke Anomia: Preliminary Data on Picture Naming Performance
Maria Martzoukou, Nefeli K. Dimitriou, Binbin Xu et al. (+4 more)
The present study evaluated the effectiveness of transcranial alternating current stimulation (tACS) treating patients with post-stroke anomia using a picture-naming task and a Single-Case Experimental Design (SCED). A right-handed 38-year-old woman with a left-hemisphere stroke and a left-handed 54-year-old man with a right-hemisphere stroke underwent an eight-week treatment program. Specifically, they participated in a picture-naming task three times a week, alternating between sessions with and without tACS stimulation every two weeks. Electroencephalography (
EEG) measurements were taken at the end of each two-week period, and behavioral data were collected before, during and after the treatment.
EEG and behavioral assessments were also conducted at one- and three-month follow-ups. Picture-naming performance was significantly faster during tACS sessions compared to sessions without tACS. By the end of the intervention, both participants demonstrated improved accuracy and speed, with positive effects also observed in behavioral measures.
EEG analysis showed that post-treatment
brain activity resembled that of healthy individuals performing similar tasks. Patients' improvements in picture-naming and behavioral tests showed that the positive effects remained stable even after three months. Thus, preliminary data suggest that tACS might be a promising intervention for anomia, with lasting effects. Large-scale studies are needed to confirm these findings.
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All authors Maria Martzoukou, Nefeli K. Dimitriou, Binbin Xu, Malo Renaud-D'Ambra, Anastasia Nousia, Anne Beuter, Grigorios Nasios
Systems and Control
Flow-based Polynomial Chaos Expansion for Uncertainty Quantification in Power System Dynamic Simulation
Le Fang, Wangkun Xu and Fei Teng
The large-scale integration of renewable energy sources introduces significant operational uncertainty into power systems. Although
Polynomial Chaos Expansion (PCE) provides an efficient tool for uncertainty quantification (UQ) in power system dynamics, its accuracy depends critically on the faithful representation of input uncertainty, an assumption that is oftern violated in practice due to correlated, non-Gaussian, and otherwise complex data distributions. In contrast to purely data-driven surrogates that often overlook rigorous input distribution modelling, this paper introduces flow-based PCE, a unified framework that couples expressive input modelling with efficient uncertainty propagation. Specifically, normalising flows are employed to learn an invertible transport map from a simple base distribution to the empirical joint distribution of uncertain inputs, and this map is then integrated directly into the PCE construction. In addition, the Map Smoothness Index (MSI) is introduced as a new metric to quantify the quality of the learned map, and smoother transformations are shown to yield more accurate PCE surrogates. The proposed Flow-based PCE framework is validated on
benchmark dynamic models, including the IEEE 14-bus system and the Great Britain transmission system, under a range of uncertainty scenarios.
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Signal Processing
Shift-Invariant Feature Attribution in the Application of Wireless Electrocardiograms
Yalemzerf Getnet, Abiy Tasissa and Waltenegus Dargie
Assigning relevance scores to the input features of a machine learning model enables to measure the contributions of the features in achieving a correct outcome. It is regarded as one of the approaches towards developing explainable models. For biomedical assignments, this is very useful for medical experts to comprehend machine-based decisions. In the analysis of electro cardiogram (ECG) signals, in particular, understanding which of the electrocardiogram samples or features contributed most for a given decision amounts to understanding the underlying cardiac phases or conditions the machine tries to explain. For the computation of relevance scores, determining the proper baseline is important. Moreover, the scores should have a distribution which is at once intuitive to interpret and easy to associate with the underline cardiac reality. The purpose of this work is to achieve these goals. Specifically, we propose a shift-invariant baseline which has a physical significance in the analysis as well as interpretation of electrocardiogram measurements. Moreover, we aggregate significance scores in such a way that they can be mapped to cardiac phases. We demonstrate our approach by inferring physical exertion from cardiac exertion using a residual network. We show that the ECG samples which achieved the highest relevance scores (and, therefore, which contributed most to the accurate recognition of the physical exertion) are those associated with the P and T waves. Index Terms Attribution, baseline, cardiovascular diseases, electrocardiogram, activity recognition, machine learning
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Image and Video Processing · Cross-listed from cs.CV
Thermal is Always Wild: Characterizing and Addressing Challenges in Thermal-Only Novel View Synthesis
M. Kerem Aydin, Vishwanath Saragadam and Emma Alexander
Thermal cameras provide reliable visibility in darkness and adverse conditions, but thermal imagery remains significantly harder to use for novel view synthesis (NVS) than visible-light images. This difficulty stems primarily from two characteristics of affordable thermal sensors. First, thermal images have extremely low dynamic range, which weakens appearance cues and limits the gradients available for optimization. Second, thermal data exhibit rapid frame-to-frame photometric fluctuations together with slow radiometric drift, both of which destabilize correspondence estimation and create high-frequency floater artifacts during view synthesis, particularly when no RGB guidance (beyond camera pose) is available. Guided by these observations, we introduce a lightweight preprocessing and splatting pipeline that expands usable dynamic range and stabilizes per-frame photometry. Our approach achieves state-of-the-art performance across thermal-only NVS
benchmarks, without requiring any
dataset-specific tuning.
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Systems and Control
Performance Analysis of LEO-Terrestrial Systems in Presence of Doppler Effect
Islam M. Tanash, Nuria Gonzalez-Prelcic and Risto Wichman
In this paper, we present a novel
stochastic geometry-based approach to analyze the effect of residual Doppler shift on orthogonal frequency-division multiple access (OFDMA) systems in low earth orbit (LEO) satellite-terrestrial networks. Focusing on multiuser systems employing common Doppler compensation, we analytically formulate the coverage probability by explicitly capturing the loss of OFDMA subcarrier orthogonality caused by geometry-induced residual Doppler through inter-carrier interference. The analysis accounts for the spatial distribution of ground terminals within the serving satellite's
cell and is validated through extensive Monte-Carlo simulations for both S-band and Ka-band settings. The results demonstrate the high accuracy of both the Doppler shift approximation and the derived coverage probability expression, while also highlighting the significant impact of residual Doppler shift, even after compensation, emphasizing the necessity of considering this effect in the design of future satellite networks.
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Systems and Control
Verifiable Error Bounds for Physics-Informed Neural KKL Observers
Hannah Berin-Costain, Harry Wang, Kirsten Morris et al. (+1 more)
This paper proposes a computable state-estimation error bound for learning-based Kazantzis–Kravaris/Luenberger (KKL) observers. Recent work learns the KKL transformation map with a physics-informed neural network (PINN) and a corresponding left-inverse map with a conventional neural network. However, no computable state-estimation error bounds are currently available for this approach. We derive a state-estimation error bound that depends only on quantities that can be certified over a prescribed region using neural network verification. We further extend the result to bounded additive measurement noise and demonstrate the guarantees on nonlinear
benchmark systems.
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All authors Hannah Berin-Costain, Harry Wang, Kirsten Morris, Jun Liu
Audio and Speech Processing · Cross-listed from cs.SD
When Demonstrations Fail: Diagnosing the Limits of In-Context Learning in Large Audio-Language Models with Progressive Cue Removal
Yen-Ting Piao, Jay Chiehen Liao, Wei-Tang Chien et al. (+5 more)
While Large Audio-
Language Models (LALMs) have been shown to exhibit degraded instruction-following capabilities, their ability to infer task patterns from in-context examples with audio remains understudied. To address this gap, we design a three-stage evaluation pipeline that progressively reduces textual guidance to systematically evaluate LALMs' in-context learning ability in the audio modality. Evaluating six LALMs across four audio understanding tasks under two output constraint categories, we uncover a consistent asymmetry across LALMs: in-context demonstrations reliably improve format compliance but fail to improve the core task performance. This suggests that LALMs can glean surface-level formatting patterns from demonstrations but may struggle to leverage cross-modal semantic grounding to reliably infer task objectives from examples with audio, highlighting potential limitations in current cross-modal integration. We further probe how demonstrations are used through two complementary analyses, demonstration label shuffling and
attention knockout on demonstration spans, both showing that LALMs leverage in-context examples primarily to establish the output label space and format rather than to learn a meaningful input-output correspondence.
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All authors Yen-Ting Piao, Jay Chiehen Liao, Wei-Tang Chien, Toshiki Ogimoto, Shang-Tse Chen, Yun-Nung Chen, Chun-Yi Lee, Shao-Yuan Lo
Systems and Control
Activate the Dual Cones: A Tight Reformulation of Conic ACOPF Constraints
Saba Rafiei and Samuel Chevalier
By exploiting the observed tightness of dual rotated second-order cone (RSOC) constraints, this paper transforms the dual of a conic ACOPF relaxation into an equivalent, non-conic problem where dual constraints are implicitly enforced through eliminated dual RSOC variables. To accomplish this, we apply the RSOC-based Jabr relaxation of ACOPF, pose its dual, and then show that all dual RSOC constraints must be tight (i.e., active) at optimality. We then construct a reduced dual maximization problem with only non-negativity constraints, avoiding the explicit RSOC inequality constraints. Numerical experiments confirm that the tight formulation recovers the same dual objective values as a mature conic solver (e.g., MOSEK via PowerModels) on various PGLib
benchmark test systems (ranging from 3- to 1354-buses). The proposed formulation has useful performance benefits, compared with its conic counterpart, and it allows us to define a bounding function which provides a guaranteed lower bound on system cost. While this paper focuses on demonstrating the correctness and validity of the proposed structural simplification, it lays the groundwork for future GPU-accelerated first-order optimization methods which can exploit the unconstrained nature of the proposed formulation.
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Systems and Control · Cross-listed from cs.GT
Meta-Learning for Repeated Bayesian Persuasion
Ata Poyraz Turna, Asrin Efe Yorulmaz and Tamer Başar
Classical
Bayesian persuasion studies how a sender influences receivers through carefully designed signaling policies within a single strategic interaction. In many real-world environments, such interactions are repeated across multiple games, creating opportunities to exploit structural similarity across tasks. In this work, we introduce Meta-Persuasion
algorithms, establishing the first line of theoretical results for both full-feedback and bandit-feedback settings in the Online
Bayesian Persuasion (OBP) and Markov Persuasion Process (MPP) frameworks. We show that our proposed meta-persuasion
algorithms achieve provably sharper regret rates under natural notions of task similarity, improving upon the best-known convergence rates for both OBP and MPP. At the same time, they recover the standard single-game guarantees when the sequence of games is picked arbitrarily. Finally, we complement our theoretical analysis with numerical experiments that highlight our regret improvements and the benefits of meta-learning in repeated persuasion environments.
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Systems and Control
A Unified Family-optimal Solution to Covariance Intersection Problems with Semidefinite Programming
Leonardo Pedroso, W. P. M. H. Heemels and Pedro Batista
Covariance intersection (CI) methods provide a principled approach to fusing estimates with unknown cross-correlations by minimizing a worst-case measure of uncertainty that is consistent with the available information. This paper shows that a generalized CI framework, called overlapping covariance intersection (OCI), unifies several existing CI formulations within a single optimization-based framework. This unification enables the characterization of family-optimal solutions for multiple CI variants, including standard CI and split covariance intersection (SCI), as solutions to a semidefinite program, for which efficient off-the-shelf solvers are available. When specialized to the corresponding settings, the proposed family-optimal solutions recover the state-of-the-art family-optimal solutions previously reported for CI and SCI. The resulting formulation facilitates the systematic design and real-time implementation of CI-based fusion methods in large-scale distributed estimation problems, such as cooperative localization.
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Audio and Speech Processing
End-to-End Multi-Task Learning for Adjustable Joint Noise Reduction and Hearing Loss Compensation
Philippe Gonzalez, Vera Margrethe Frederiksen, Torsten Dau et al. (+1 more)
A multi-task learning framework is proposed for optimizing a single deep neural network (DNN) for joint noise reduction (NR) and hearing loss compensation (HLC). A distinct training objective is defined for each task, and the DNN predicts two time-frequency masks. During inference, the amounts of NR and HLC can be adjusted independently by exponentiating each mask before combining them. In contrast to recent approaches that rely on training an auditory-model emulator to define a differentiable training objective, we propose an auditory model that is inherently differentiable, thus allowing end-to-end optimization. The audiogram is provided as an input to the DNN, thereby enabling listener-specific personalization without the need for retraining. Results show that the proposed approach not only allows adjusting the amounts of NR and HLC individually, but also improves objective metrics compared to optimizing a single training objective. It also outperforms a cascade of two DNNs that were separately trained for NR and HLC, and shows competitive HLC performance compared to a traditional hearing-aid prescription. To the best of our knowledge, this is the first study that uses an auditory model to train a single DNN for both NR and HLC across a wide range of listener profiles.
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All authors Philippe Gonzalez, Vera Margrethe Frederiksen, Torsten Dau, Tobias May
Signal Processing
Cost-Aware Neural Early Stopping for Local Constraint OSD Decoders
Talha Akyildiz and Hessam Mahdavifar
Local constraint ordered statistics decoding (LC-OSD) provides strong soft decision performance for short block length linear codes, but its practical cost is dominated by the number of tested error patterns (TEPs). This paper proposes a neural early stopping (NES) protocol for LC-OSD with explicit cost control through one trade-off parameter balancing frame error risk and search effort. The proposed approach is trained with frame error rate (FER)-aligned supervision at predefined checkpoints, and learns if additional search is still likely to improve the current best candidate. Later, stopping is decided by comparing predicted continuation need with a cost measured in TEPs. Experimental results across multiple code families show that the proposed protocol significantly reduces average TEP count with only marginal FER degradation, using a single global model for the range of all operating signal-to-noise ratios (SNRs).
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Image and Video Processing
CaroTo: A Tool for Fast Comprehensive Analysis of Carotid Artery Stenosis in 4D PC- and 3D BB-MRI Data
Hinrich Rahlfs, Markus Hüllebrand, Sebastian Schmitter et al. (+4 more)
Atherosclerosis of the carotid artery increases stroke risk. Atherosclerosis assessment with MRI requires
multimodal and multidimensional
segmentation of the carotid artery, reproducible extraction of biomarkers, and the visualization of
segmentations and biomarkers. We developed CaroTo, a tool that allows for standardized carotid atherosclerosis assessment. It combines the capabilities of MEVISFlow with specialized tools for carotid geometry and vessel wall assessment. It supports manual and automatic
segmentation for 2D, 2D+time, and 3D images, facilitating precise and consistent evaluations of carotid artery stenosis.
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All authors Hinrich Rahlfs, Markus Hüllebrand, Sebastian Schmitter, Jonathan Andrae, Christoph Strecker, Andreas Harloff, Anja Hennemuth
Image and Video Processing · Cross-listed from cs.CV
Scene Representation using 360{\deg} Saliency Graph and its Application in Vision-based Indoor Navigation
Preeti Meena, Himanshu Kumar and Sandeep Yadav
A Scene, represented visually using different formats such as RGB-D,
LiDAR scan, keypoints, rectangular, spherical, multi-views, etc., contains information implicitly embedded relevant to applications such as scene indexing,
vision-based
navigation. Thus, these representations may not be efficient for such applications. This paper proposes a novel 360{\deg} saliency graph representation of the scenes. This rich representation explicitly encodes the relevant visual, contextual, semantic, and
geometric information of the scene as nodes, edges, edge weights, and angular position in the 360{\deg} graph. Also, this representation is robust against scene view change and addresses challenges of indoor environments such as varied illumination, occlusions, and shadows as in the case of existing traditional methods. We have utilized this rich and efficient representation for
vision-based
navigation and compared it with existing
navigation methods using 360{\deg} scenes. However, these existing methods suffer from limitations of poor scene representation, lacking scene-specific information. This work utilizes the proposed representation first to localize the query scene in the given topological map, and then facilitate 2D
navigation by estimating the next required movement directions towards the target destination in the topological map by using the embedded
geometric information in the 360{\deg} saliency graph. Experimental results demonstrate the efficacy of the proposed 360{\deg} saliency graph representation in enhancing both scene localization and
vision-based indoor
navigation.
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Signal Processing
Framework for Indoor Wireless Propagation Modeling Through Wireless Insite
Arao Zau Macaia, Niraj Narayan, Rajeev Shukla et al. (+8 more)
Multipaths, reflections, diffractions, and material interactions complicate indoor wireless propagation modelling. More than 80% of wireless data is consumed indoors; hence, planning successful deployments and maximizing network performance depends on accurate propagation modelling of indoor environments. This work explains a complete framework for indoor wireless propagation modelling via ray tracing simulation in a step-by-step manner. The ray tracing simulations are conducted with Wireless Insite, a proprietary electromagnetic propagation software, whereas SketchUp is used at the input side for layout construction from the field measurements, and MATLAB is used at the output side for portraying channel model parameters such as power delay profile (PDP). A whole floor of the authors' department is modelled, and different transmitter-receiver locations were tested for possible use cases such as coverage hole prediction.
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All authors Arao Zau Macaia, Niraj Narayan, Rajeev Shukla, Aniruddha Chandra, Ondrej Zeleny, Radek Zavorka, Jiri Blumenstein, Ales Prokes, Jaroslaw Wojtun, Jan M. Kelner, Cezary Ziolkowski
Systems and Control · Cross-listed from cs.LG
Learning Sampled-data Control for Swarms via MeanFlow
Anqi Dong, Yongxin Chen, Karl H. Johansson et al. (+1 more)
Steering large-scale swarms with only limited control updates is often needed due to communication or computational constraints, yet most learning-based approaches do not account for this and instead model instantaneous velocity fields. As a result, the natural object for decision making is a finite-window control quantity rather than an infinitesimal one. To address this gap, we consider the recent machine learning framework MeanFlow and generalize it to the setting with general linear dynamic systems. This results in a new sampled-data learning framework that operates directly in control space and that can be applied for swarm steering. To this end, we learn the finite-horizon coefficient that parameterizes the minimum-energy control applied over each interval, and derive a differential identity that connects this quantity to a local bridge-induced supervision signal. This identity leads to a simple stop-gradient regression objective, allowing the interval coefficient field to be learned efficiently from bridge samples. The learned policy is deployed through sampled-data updates, guaranteeing that the resulting controller exactly respects the prescribed linear time-invariant dynamics and actuation channel. The resulting method enables few-step swarm steering at scale, while remaining consistent with the finite-window actuation structure of the underlying control system.
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All authors Anqi Dong, Yongxin Chen, Karl H. Johansson, Johan Karlsson
Audio and Speech Processing · Cross-listed from cs.SD
Audio Avatar Fingerprinting: An Approach for Authorized Use of Voice Cloning in the Era of Synthetic Audio
Candice R. Gerstner
With the advancements in AI
speech synthesis, it is easier than ever before to generate realistic audio in a target voice. One only needs a few seconds of reference audio from the target, quite literally putting words in the target person's mouth. This imposes a new set of forensics-related challenges on
speech-based authentication systems, videoconferencing, and audio-visual broadcasting platforms, where we want to detect synthetic
speech. At the same time, leveraging AI
speech synthesis can enhance the different modes of communication through features such as low-bandwidth communication and audio enhancements - leading to ever-increasing legitimate use-cases of synthetic audio. In this case, we want to verify if the synthesized voice is actually spoken by the user. This will require a mechanism to verify whether a given synthetic audio is driven by an authorized identity, or not. We term this task audio avatar fingerprinting. As a step towards audio forensics in these new and emerging situations, we analyze and extend an off-the-shelf speaker verification model developed outside of forensics context for the task of fake
speech detection and audio avatar fingerprinting, the first experimentation of its kind. Furthermore, we observe that no existing
dataset allows for the novel task of verifying the authorized use of synthetic audio - a limitation which we address by introducing a new
speech forensics
dataset for this novel task.
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Systems and Control
Robust Linear Quadratic Optimal Control of Cementitious Material Extrusion
Mandana Mohammadi Looey, Amrita Basak and Satadru Dey
Extrusion-based 3D printing of cementitious materials enables fabrication of complex structures, however it is highly sensitive to disturbances, material property variations, and process uncertainties that decrease flow stability and dimensional fidelity. To address these challenges, this study proposes a robust linear quadratic optimal control framework for regulating material extrusion in cementitious direct ink writing systems. The printer is modeled using two coupled subsystems: an actuation system representing nozzle flow dynamics and a printing system describing the printed strand flow on the build plate. A hybrid control architecture combining sliding mode control for disturbance rejection with linear quadratic optimal feedback for energy-efficient tracking is developed to ensure robustness and optimality. In simulation case studies, the control architecture guarantees acceptable convergence of nozzle and strand flow tracking errors under bounded disturbances.
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