Image and Video Processing
Linear Algebraic Approaches to Neuroimaging Data Compression: A Comparative Analysis of Matrix and Tensor Decomposition Methods for High-Dimensional Medical Images
Jaeho Kim, Daniel David and Ana Vizitiv
This paper evaluates Tucker decomposition and Singular Value Decomposition (SVD) for compressing neuroimaging data. Tucker decomposition preserves multi-dimensional relationships, achieving superior reconstruction fidelity and perceptual similarity. SVD excels in extreme compression but sacrifices fidelity. The results highlight Tucker decomposition's suitability for applications requiring the preservation of structural and temporal relationships.
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Systems and Control
Energy Control Strategy to Enhance AC Fault Ride-Through in Offshore Wind MMC-HVDC Systems
Dileep Kumar and Wajiha Shireen
Modular Multilevel Converter-based High Voltage Direct Current (MMC-HVDC) system is a promising technology for integration of offshore wind farms (OWFs). However, onshore AC faults on MMC-HVDC reduce the power transfer capability of onshore converter station, leading to surplus power accumulation in HVDC link. This surplus power causes a rapid rise in DC-link voltage and may hinder safe operation of OWFs. To address such a situation, this paper presents an AC fault ride-through scheme that combines the storage of surplus power in MMC submodule (SM) capacitors and dissipation of residual power in an energy dissipation device (EDD). The proposed energy control facilitates use of half-bridge MMC SMs with low-capacitance, with their storage capacity leveraged to share the surplus power during faults, with a lower-rated EDD. The proposed scheme is tested on a 640kV/420MW MMC-HVDC system. The results show that proposed control scheme effectively maintains DC link voltages, ensuring connection of OWFs.
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Systems and Control
Optimizing the Driving Profile for Vehicle Mass Estimation – extended version
Le Wang, Jessica Ye, Michael Refors et al. (+2 more)
Accurate mass estimation is essential for the safe and efficient operation of autonomous heavy-duty vehicles, particularly during transportation missions in unstructured environments such as mining sites, where vehicle mass can vary significantly due to loading and unloading. While prior work has recognized the importance of acceleration profiles for estimation accuracy, the systematic design of driving profiles during transport has not been thoroughly investigated. This paper presents a framework for designing driving profiles to support accurate mass estimation. Based on application-oriented input design, it aims to meet a user-defined accuracy constraint under three optimization objectives: minimum-time, minimum-distance, and maximum accuracy (within a fixed time). It allows time- and distance-dependent bounds on acceleration and velocity, and is based on a Newtonian vehicle dynamics model with actuator dynamics. The optimal profiles are obtained by solving concave optimization problems using a branch-and-bound method, with alternative rank-constrained and semi-definite relaxations also discussed. Theoretical analysis provides insights into the optimal profiles, including feasibility conditions, key ratios between velocity and acceleration bounds, and trade-offs between time- and distance-optimal solutions. The framework is validated through simulations and real-world experiments on a Scania truck with different payloads. Results show that the designed profiles are feasible and effective, enabling accurate mass estimation as part of normal transportation operations without requiring dedicated calibration runs. An additional contribution is a non-causal Wiener filter, with parameters estimated via the Empirical Bayes method, used to filter the accelerometer signal with no phase-lag.
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All authors Le Wang, Jessica Ye, Michael Refors, Oscar Flärdh, Håkan Hjalmarsson
Systems and Control
Real-Time Lane-Level Crash Detection on Freeways Using Sparse Telematics Data
Shixiao Liang, Chengyuan Ma, Pei Li et al. (+7 more)
Real-time traffic crash detection is critical in intelligent transportation systems because traditional crash notifications often suffer delays and lack specific, lane-level location information, which can lead to safety risks and economic losses. This paper proposes a real-time, lane-level crash detection approach for freeways that only leverages sparse telematics trajectory data. In the offline stage, the historical trajectories are discretized into spatial
cells using vector cross-product techniques, and then used to estimate a vehicle intention distribution and select an alert threshold by maximizing the F1-score based on official crash reports. In the online stage, incoming telematics records are mapped to these
cells and scored for three modules: transition anomalies, speed deviations, and lateral maneuver risks, with scores accumulated into a
cell-specific risk map. When any
cell's risk exceeds the alert threshold, the system issues a
prompt warning. Relying solely on telematics data, this real-time and low-cost solution is evaluated on a Wisconsin
dataset and validated against official crash reports, achieving a 75% crash identification rate with accurate lane-level localization, an overall accuracy of 96%, an F1-score of 0.84, and a non-crash-to-crash misclassification rate of only 0.6%, while also detecting 13% of crashes more than 3 minutes before the recorded crash time.
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All authors Shixiao Liang, Chengyuan Ma, Pei Li, Haotian Shi, Jiaxi Liu, Hang Zhou, Keke Long, Bofeng Cao, Todd Szymkowski, Xiaopeng Li
Signal Processing
Precise Localization of High-Voltage Breakdown Events using $\phi$-Optical Time-Domain Reflectometry on an Optical Ground Wire
Konstantinos Alexoudis, Luke Silvestre, Tom Huiskamp et al. (+6 more)
We present $\phi$-OTDR for detecting and localising full spark-gap breakdowns by analysing backscattered light phase and frequency-domain signatures during high-voltage discharges synchronised with oscilloscope-recorded events. Measuring sub-kHz confirms clear discharge signatures and acoustic reconstruction over long links with $\approx$ 10 m spatial resolution.
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All authors Konstantinos Alexoudis, Luke Silvestre, Tom Huiskamp, Jasper Müller, Vincent Sleiffer, Florian Azendorf, Sander Jansen, Chigo Okonkwo, Tom Bradley
Systems and Control · Cross-listed from cs.RO
Anti-Jamming based on Null-Steering Antennas and Intelligent UAV Swarm Behavior
Miguel Lourenço and António Grilo
Unmanned Aerial Vehicle (
UAV) swarms represent a key advancement in autonomous systems, enabling coordinated missions through inter-
UAV communication. However, their reliance on wireless links makes them vulnerable to jamming, which can disrupt coordination and mission success. This work investigates whether a
UAV swarm can effectively overcome jamming while maintaining communication and mission efficiency. To address this, a unified optimization framework combining Genetic
Algorithms (GA), Supervised Learning (SL), and Reinforcement Learning (RL) is proposed. The mission model, structured into epochs and timeslots, allows dynamic path planning,
antenna orientation, and swarm formation while progressively enforcing collision rules. Null-steering
antennas enhance resilience by directing
antenna nulls toward interference sources. Results show that the GA achieved stable, collision-free trajectories but with high computational cost. SL models replicated GA-based configurations but struggled to generalize under dynamic or constrained settings. RL, trained via Proximal Policy Optimization (PPO), demonstrated adaptability and real-time decision-making with consistent communication and lower computational demand. Additionally, the Adaptive Movement Model generalized
UAV motion to arbitrary directions through a rotation-based mechanism, validating the scalability of the proposed system. Overall,
UAV swarms equipped with null-steering
antennas and guided by intelligent optimization
algorithms effectively mitigate jamming while maintaining communication stability, formation cohesion, and collision safety. The proposed framework establishes a unified, flexible, and reproducible basis for future research on resilient swarm communication systems.
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Systems and Control
Sparse Broad Learning System via Sequential Threshold Least-Squares for Nonlinear System Identification under Noise
Zijing Li
The Broad Learning System (BLS) has gained significant
attention for its computational efficiency and less network parameters compared to deep learning structures. However, the standard BLS relies on the pseudoinverse solution, which minimizes the mean square error with $L_2$-norm but lacks robustness against sensor noise and outliers common in industrial environments. To address this limitation, this paper proposes a novel Sparse Broad Learning System (S-BLS) framework. Instead of the traditional ridge regression, we incorporate the Sequential Threshold Least-Squares (STLS)
algorithm – originally utilized in the sparse identification of nonlinear dynamics (SINDy) – into the output weight learning process of BLS. By iteratively thresholding small coefficients, the proposed method promotes sparsity in the output weights, effectively filtering out noise components while maintaining modeling accuracy. This approach falls under the category of sparse regression and is particularly suitable for noisy environments. Experimental results on a numerical nonlinear system and a noisy Continuous Stirred Tank Reactor (CSTR)
benchmark demonstrate that the proposed method is effective and achieves superior robustness compared to standard BLS.
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Signal Processing · Cross-listed from q-bio.NC
The Hydraulic Brain: Understanding as Constraint-Release Phase Transition in Whole-Body Resonance
Ahmed Gamal Eldin
Current models treat physiological signals as noise corrupting neural computation. Previously, we showed that removing these "artifacts" eliminates 70% of predictive correlation, suggesting body signals functionally drive cognition. Here, we investigate the mechanism using high-density
EEG (64 channels, 10 subjects, 500+ trials) during P300 target recognition. Phase Slope Index revealed zero-lag synchrony (PSI=0.000044, p=0.061) with high coherence (0.316, p<0.0001). Ridge-regularized Granger causality showed massive bidirectional coupling (F=100.53
brain-to-body, F=62.76 body-to-
brain) peaking simultaneously at 78.1ms, consistent with mutually coupled resonance pairs. Time-resolved
entropy analysis (200ms windows, 25ms steps) revealed triphasic dynamics: (1) constraint accumulation (0-78ms) building causal drive without
entropy change (delta-S=-0.002 bits, p=0.75); (2) supercritical transition (100-600ms) triggering state expansion (58% directional increase, binomial p=0.002); (3) sustained metastability. Critically, transition magnitude was uncorrelated with resonance strength (r=-0.044, p=0.327), indicating binary threshold dynamics. Understanding emerges through a thermodynamic sequence:
brain-body resonance acts as a discrete gate triggering non-linear information integration. This architecture may fundamentally distinguish biological from artificial intelligence. Keywords:
embodied cognition, phase transitions, Granger causality, thermodynamics, neuromorphic computing, resonance dynamics,
EEG artifacts
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Systems and Control
Sparse Kalman Identification for Partially Observable Systems via Adaptive Bayesian Learning
Jilan Mei, Tengjie Zheng, Lin Cheng et al. (+2 more)
Sparse dynamics identification is an essential tool for discovering interpretable physical models and enabling efficient control in engineering systems. However, existing methods rely on batch learning with full historical data, limiting their applicability to real-time scenarios involving sequential and partially observable data. To overcome this limitation, this paper proposes an online Sparse Kalman Identification (SKI) method by integrating the Augmented Kalman Filter (AKF) and Automatic Relevance Determination (ARD). The main contributions are: (1) a theoretically grounded
Bayesian sparsification scheme that is seamlessly integrated into the AKF framework and adapted to sequentially collected data in online scenarios; (2) an update mechanism that adapts the Kalman posterior to reflect the updated selection of the basis functions that define the model structure; (3) an explicit gradient-descent formulation that enhances computational efficiency. Consequently, the SKI method achieves accurate model structure selection with millisecond-level efficiency and higher identification accuracy, as demonstrated by extensive simulations and real-world experiments (showing an 84.21% improvement in accuracy over the baseline AKF).
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All authors Jilan Mei, Tengjie Zheng, Lin Cheng, Shengping Gong, Xu Huang
Image and Video Processing
Diverse Instance Generation via Diffusion Models for Enhanced Few-Shot Object Detection in Remote Sensing Images
Yanxing Liu, Jiancheng Pan, Jianwei Yang et al. (+3 more)
Few-shot object detection (FSOD) aims to detect novel instances with only a limited number of labeled training samples, presenting a challenge that is particularly prominent in numerous remote sensing applications such as endangered species monitoring and disaster assessment. Existing FSOD methods for remote sensing images (RSIs) have achieved promising progress but remain constrained by the limited diversity of instances. To address this issue, we propose a novel framework that can leverage a
diffusion model pretrained on large-scale natural images to synthesize diverse remote sensing instances, thereby improving the performance of few-shot object detectors. Instead of directly synthesizing complete remote sensing images, we first generate instance-level slices via a specialized slice-to-slice module, and then embed these slices into full-scale imagery for enhanced data augmentation. To further adapt
diffusion models for remote sensing scenarios, we develop a class-agnostic image inversion module that can invert remote sensing instance slices into semantic space. Additionally, we introduce contrastive loss to semantically align the synthesized images with their corresponding classes. Experimental results show that our method hasachieved an average performance improvement of 4.4% across multiple
datasets and various approaches. Ablation experiments indicate that the elaborately designed inversion module can effectively enhance the performance of FSOD methods, and the semantic contrastive loss can further boost the performance.
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All authors Yanxing Liu, Jiancheng Pan, Jianwei Yang, Tiancheng Chen, Peiling Zhou, Bingchen Zhang
Systems and Control
On the stability of event-based control with neuronal dynamics
Luke Eilers, Jonas Stapmanns, Catarina Dias et al. (+1 more)
Event-based control, unlike analogue control, poses significant analytical challenges due to its hybrid dynamics. This work investigates the stability and inter-event time properties of a control-affine system under event-based impulsive control. The controller consists of multiple neuronal units with leaky integrate-and-fire dynamics acting on a time-invariant, multivariable plant in closed loop. Both the plant state and the neuronal units exhibit discontinuities that cancel if combined linearly, enabling a direct correspondence between the event-based impulsive controller and a corresponding analogue controller. Leveraging this observation, we prove global practical stability of the event-based impulsive control system. In the general nonlinear case, we show that the event-based impulsive controller ensures global practical asymptotic stability if the analogue system is input-to-state stable (ISS) with respect to specific disturbances. In the linear case, we further show global practical exponential stability if the analogue system is stable. We illustrate our results with numerical simulations. The findings reveal a fundamental link between analogue and event-based impulsive control, providing new insights for the design of neuromorphic controllers.
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All authors Luke Eilers, Jonas Stapmanns, Catarina Dias, Jean-Pascal Pfister
Signal Processing
Channel Estimation for RIS-Aided MU-MIMO mmWave Systems with Direct Channel Links
Taihao Zhang, Zhendong Peng, Cunhua Pan et al. (+2 more)
In this paper, we propose a three-stage unified channel estimation strategy for reconfigurable intelligent surface (RIS)-aided multi-user (MU) multiple-input multiple-output (
MIMO) millimeter wave (mmWave) systems with the existence of the direct channels, where the base station (BS), the users and the RIS are equipped with uniform planar array (UPA). The effectiveness of the developed three-stage strategy stems from the careful design of both the pilot signal sequence of the users and the vectors of RIS. Specifically, in Stage I, the cascaded channel components are eliminated by configuring the RIS phase shift vectors with a {\pi} difference to estimate the direct channels for all users. The orthogonal subspace projection is employed in Stage II to obtain equivalent signal
matrices, enabling the estimation of angles of departure (AoDs) of the user-RIS channel for all users. In Stage III, we combine the signals of the time slots with the same pilots and project obtained measurement
matrix to the orthogonal complement space of the component consisting of the portion of the direct channel, which removes the direct components and thus prevents error propagation from the direct channels to the cascaded channels. Then, we estimate the angles of arrival (AoAs) of the RIS-BS channel and remaining parameters of the cascaded channel for all users by exploiting the sparsity and correlation in the obtained equivalent
matrices. Simulation results demonstrate that the proposed method yields better estimation performance than the existing methods.
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All authors Taihao Zhang, Zhendong Peng, Cunhua Pan, Hong Ren, Jiangzhou Wang
Signal Processing
Orthogonal Chirp Delay-Doppler Division Multiplexing (CDDM) Modulation for High Mobility Communications
Chaoyuan Bai, Pingzhi Fan, Zhengchun Zhou et al. (+1 more)
This paper proposes a novel multi-carrier modulation framework for high-mobility communication scenarios. Our key idea lies in spreading data symbols across the delay-Doppler (DD) domain through orthogonal chirp-Zak transform (CZT). To enable efficient signal multiplexing, the proposed modulation scheme employs a transmitter signal that maintains orthogonality with the inherent resolution characteristics of the DD plane. Termed as Orthogonal Chirp Delay-Doppler Division Multiplexing (CDDM), we demonstrate a synergistic integration of chirp waveform properties with the channel structure of the DD domain, thereby achieving advantages with both lower computational efficiency and improved detection performance. We introduce a novel CZT-based superimposed sparse pilot structure to enable simultaneous estimation of delay-Doppler shifts and channel coefficients. For enhanced performance, we further develop an embedded pilot scheme that demonstrates channel estimation performance comparable to that of Orthogonal Delay-Doppler Division Multiplexing (ODDM) systems. Simulation results demonstrate that CDDM achieves significant bit error rate (BER) improvements over existing modulation schemes , under perfect channel state information (CSI), as well as superior out-of-band emissions (OOBE). Further, for the imperfect CSI case, the proposed CZT-based superimposed pilot scheme leads to significantly reduced normalized mean square error (NMSE), whilst attaining equivalent estimation accuracy to that of ODDM with lower computational complexity.
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All authors Chaoyuan Bai, Pingzhi Fan, Zhengchun Zhou, Zilong Liu
Signal Processing
On the Performance of Dual-Antenna Repeater Assisted Bi-Static MIMO ISAC
Anubhab Chowdhury and Erik G. Larsson
This paper presents a framework for target detection and downlink data transmission in a repeater-assisted bi-static integrated sensing and communication system. A repeater is an active scatterer that retransmits incoming signals with a complex gain almost instantaneously, thereby enhancing sensing performance by amplifying the echoes reflected by the targets. The same mechanism can also improve downlink communication by mitigating coverage holes. However, the repeater introduces noise and increases interference at the sensing receiver, while also amplifying the interference from target detection signals at the downlink users. The proposed framework accounts for these sensing-communication trade-offs and demonstrates the potential benefits achievable through a carefully designed precoder at the transmitting base station. In particular, our finding is that a higher value of probability of detection can be attained with considerably lower target radar-cross-section variance by deploying repeaters in the target hot-spot areas.
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Signal Processing · Cross-listed from cs.IT
A Reinforcement Learning Framework for Resource Allocation in Uplink Carrier Aggregation in the Presence of Self Interference
Jaswanth Bodempudi, Batta Siva Sairam, Madepalli Haritha et al. (+2 more)
Carrier aggregation (CA) is a technique that allows mobile networks to combine multiple carriers to increase user data rate. On the uplink, for power constrained users, this translates to the need for an efficient resource allocation scheme, where each user distributes its available power among its assigned uplink carriers. Choosing a good set of carriers and allocating appropriate power on the carriers is important. If the carrier allocation on the uplink is such that a harmonic of a user's uplink carrier falls on the downlink frequency of that user, it leads to a self coupling-induced sensitivity degradation of that user's downlink receiver. In this paper, we model the uplink carrier aggregation problem as an optimal resource allocation problem with the associated constraints of non-linearities induced self interference (SI). This involves optimization over a discrete variable (which carriers need to be turned on) and a continuous variable (what power needs to be allocated on the selected carriers) in dynamic environments, a problem which is hard to solve using traditional methods owing to the mixed nature of the optimization variables and the additional need to consider the SI constraint. We adopt a reinforcement learning (RL) framework involving a compound-action actor-critic (CA2C)
algorithm for the uplink carrier aggregation problem. We propose a novel reward function that is critical for enabling the proposed CA2C
algorithm to efficiently handle SI. The CA2C
algorithm along with the proposed reward function learns to assign and activate suitable carriers in an online fashion. Numerical results demonstrate that the proposed RL based scheme is able to achieve higher sum throughputs compared to naive schemes. The results also demonstrate that the proposed reward function allows the CA2C
algorithm to adapt the optimization both in the presence and absence of SI.
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All authors Jaswanth Bodempudi, Batta Siva Sairam, Madepalli Haritha, Sandesh Rao Mattu, Ananthanarayanan Chockalingam
Image and Video Processing
Radiative-Structured Neural Operator for Continuous Spectral Super-Resolution
Ziye Zhang, Bin Pan and Zhenwei Shi
Spectral super-resolution (SSR) aims to reconstruct hyperspectral images (HSIs) from multispectral observations, with broad applications in computer
vision and remote sensing. Deep learning-based methods have been widely used, but they often treat spectra as discrete vectors learned from data, rather than continuous curves constrained by physics principles, leading to unrealistic predictions and limited applicability. To address this challenge, we propose the Radiative-Structured Neural Operator (RSNO), which learns a continuous mapping for spectral super-resolution while enforcing physical consistency under the radiative prior. The proposed RSNO consists of three stages: upsampling, reconstruction, and refinement. In the upsampling stage, we leverage prior information to expand the input multispectral image, producing a physically plausible hyperspectral estimate. Subsequently, we adopt a neural operator backbone in the reconstruction stage to learn a continuous mapping across the spectral domain. Finally, the refinement stage imposes a hard constraint on the output HSI to eliminate color distortion. The upsampling and refinement stages are implemented via the proposed angular-consistent projection (ACP), which is derived from a non-convex optimization problem. Moreover, we theoretically demonstrated the optimality of ACP by null-space decomposition. Various experiments validate the effectiveness of the proposed approach in both discrete and continuous spectral super-resolution.
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Systems and Control
Machine Learning-based Online Stability Lobe Diagram Estimation and Chatter Suppression Control in Milling Process
Yi Huang, Feng Han, Wenyi Liu et al. (+2 more)
Chatter is a self-excited vibration in milling that degrades surface quality and accelerates tool wear. This paper presents an adaptive process controller that suppresses chatter by leveraging machine learning-based online estimation of the Stability Lobe Diagram (SLD) and surface roughness in the process. Stability analysis is conducted using the semi-discretization method for milling dynamics modeled by delay differential equations. An integrated machine learning framework estimates the SLD from sensor data and predicts surface roughness for chatter detection in real time. These estimates are integrated into an optimal controller that adaptively adjusts spindle speed to maintain process stability and improve surface finish. Simulations and experiments are performed to demonstrate the superior performance compared to the existing approaches.
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All authors Yi Huang, Feng Han, Wenyi Liu, Jingang Yi, Yuebin Guo
Signal Processing
OFDM-ISAC Beyond CP Limit: Performance Analysis and Mitigation Algorithms
Peishi Li, Ming Li, Rang Liu et al. (+2 more)
Orthogonal frequency division multiplexing (OFDM) is well-suited for integrated sensing and communications (
ISAC), yet its cyclic prefix (CP) is dimensioned for communications-grade multipath and is generally insufficient for sensing. When echoes exceed the CP duration, inter-symbol and inter-carrier interference (ISI/ICI) break subcarrier orthogonality and degrade sensing. This paper presents a unified analytical and algorithmic framework for OFDM-
ISAC beyond the CP limit. We first develop a general echo model that explicitly captures the structured coupling of ISI and ICI caused by CP insufficiency. Building on this model, we derive closed-form signal-to-interference-plus-noise ratio (SINR) and range-Doppler Map (RDM) second-order moment, together with an approximate peak sidelobe level ratio (PSLR), both of which are shown to deteriorate approximately linearly with the normalized excess delay beyond the CP. To mitigate these effects, we propose two standard-compatible successive interference cancellation (SIC) methods: SIC-DFT, a low-complexity DFT-based scheme, and SIC-ESPRIT, a super-resolution subspace approach. Simulations corroborate the analysis and demonstrate consistent gains over representative
benchmarks. Both
algorithms provide more than $4$~dB SINR improvement under CP-insufficient conditions, while SIC-ESPRIT reduces range/velocity root-mean-square-errors (RMSE) by about one order of magnitude, approaching the performance achievable with a sufficiently long CP. These results offer both theoretical insight and practical solutions for reliable long-range OFDM-
ISAC sensing beyond the CP limit.
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All authors Peishi Li, Ming Li, Rang Liu, Qian Liu, A. Lee Swindlehurst
Image and Video Processing
TransLK-Net: Entangling Transformer and Large Kernel for Progressive and Collaborative Feature Encoding and Decoding in Medical Image Segmentation
Jin Yang, Daniel S.Marcus and Aristeidis Sotiras
Convolutional neural networks (CNNs) and
vision transformers (ViTs) are widely employed for medical image
segmentation, but they are still challenged by their intrinsic characteristics. CNNs are limited from capturing varying-scaled features and global contextual information due to the employment of fixed-sized kernels. In contrast, ViTs employ self-
attention and MLP for global information modeling, but they lack mechanisms to learn spatial-wise local information. Additionally, self-
attention leads the network to show high computational complexity. To tackle these limitations, we propose Progressively Entangled
Transformer Large Kernel (PTLK) and Collaboratively Entangled
Transformer Large Kernel (CTLK) modules to leverage the benefits of self-
attention and large kernel convolutions and overcome shortcomings. Specifically, PTLK and CTLK modules employ the Multi-head Large Kernel to capture multi-scale local features and the Efficient Decomposed Self-
attention to model global information efficiently. Subsequently, they employ the
Attention Entanglement mechanism to enable local and global features to enhance and calibrate each other progressively and collaboratively. Additionally, an
Attention-gated Channel MLP (AG-MLP) module is proposed to equip the standard MLP module with the capabilities of modeling spatial information. PTLK and CTLK modules are further incorporated as a Cross
Entanglement Decoding (CED) block for efficient feature fusion and decoding. Finally, we propose a novel network for volumetric medical image
segmentation that employs an encoder-decoder architecture, termed TransLK-Net. The encoder employs a hierarchical ViT architecture whose block is built by incorporating PTLK and CTLK with AG-MLP into a ViT block, and the decoder employs the CED block.
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Image and Video Processing
INT-DTT+: Low-Complexity Data-Dependent Transforms for Video Coding
Samuel Fernández-Menduiña, Eduardo Pavez, Antonio Ortega et al. (+4 more)
Discrete trigonometric transforms (DTTs), such as the DCT-2 and the DST-7, are widely used in
video codecs for their balance between coding performance and computational efficiency. In contrast, data-dependent transforms, such as the Karhunen-Loève transform (KLT) and graph-based separable transforms (GBSTs), offer better energy compaction but lack
symmetries that can be exploited to reduce computational complexity. This paper bridges this gap by introducing a general framework to design low-complexity data-dependent transforms. Our approach builds on DTT+, a family of GBSTs derived from rank-one updates of the DTT graphs, which can adapt to signal statistics while retaining a structure amenable to fast computation. We first propose a graph learning
algorithm for DTT+ that estimates the rank-one updates for rows and column graphs jointly, capturing the statistical properties of the overall block. Then, we exploit the progressive structure of DTT+ to decompose the kernel into a base DTT and a structured Cauchy
matrix. By leveraging low-complexity integer DTTs and sparsifying the Cauchy
matrix, we construct an integer approximation to DTT+, termed INT-DTT+. This approximation significantly reduces both computational and
memory complexities with respect to the separable KLT with minimal performance loss. We validate our approach in the context of mode-dependent transforms for the VVC standard, following a rate-distortion optimized transform (RDOT) design approach. Integrated into the explicit multiple transform selection (MTS) framework of VVC in a rate-distortion optimization setup, INT-DTT+ achieves more than 3% BD-rate savings over the VVC MTS baseline, with complexity comparable to the integer DCT-2 once the base DTT coefficients are available.
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All authors Samuel Fernández-Menduiña, Eduardo Pavez, Antonio Ortega, Tsung-Wei Huang, Thuong Nguyen Canh, Guan-Ming Su, Peng Yin
Systems and Control
Generative Model Predictive Control in Manufacturing Processes: A Review
Suk Ki Lee, Ronnie F. P. Stone, Max Gao et al. (+3 more)
Manufacturing processes are inherently dynamic and uncertain, with varying parameters and nonlinear behaviors, making robust control essential for maintaining quality and reliability. Traditional control methods often fail under these conditions due to their reactive nature. Model Predictive Control (MPC) has emerged as a more advanced framework, leveraging process models to predict future states and optimize control actions. However, MPC relies on simplified models that often fail to capture complex dynamics, and it struggles with accurate state estimation and handling the propagation of uncertainty in manufacturing environments. Machine learning (ML) has been introduced to enhance MPC by modeling nonlinear dynamics and learning latent representations that support predictive modeling, state estimation, and optimization. Yet existing ML-driven MPC approaches remain deterministic and correlation-focused, motivating the exploration of generative. Generative ML offers new opportunities by learning data distributions, capturing hidden patterns, and inherently managing uncertainty, thereby complementing MPC. This review highlights five representative methods and examines how each has been integrated into MPC components, including predictive modeling, state estimation, and optimization. By synthesizing these cases, we outline the common ways generative ML can systematically enhance MPC and provide a framework for understanding its potential in diverse manufacturing processes. We identify key research gaps, propose future directions, and use a representative case to illustrate how generative ML-driven MPC can extend broadly across manufacturing. Taken together, this review positions generative ML not as an incremental add-on but as a transformative approach to reshape predictive control for next-generation manufacturing systems.
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All authors Suk Ki Lee, Ronnie F. P. Stone, Max Gao, Wenlong Zhang, Zhenghui Sha, Hyunwoong Ko
Image and Video Processing
A Versatile Optical Frontend for Multicolor Fluorescence Imaging with Miniaturized Lensless Sensors
Lukas Harris, Micah Roschelle, Jack Bartley et al. (+1 more)
Lensless imaging enables exceptionally compact fluorescence sensors, advancing applications in in vivo imaging and low-cost, point-of-care diagnostics. These sensors require a filter to block the excitation light while passing fluorescent emissions. However, conventional thin-film interference filters are sensitive to angle of incidence (AOI), complicating their use in lensless systems. Here we thoroughly analyze and optimize a technique using a fiber optic plate (FOP) to absorb off-axis light that would bleed through the interference filter while improving image resolution. Through simulations, we show that the numerical aperture (NA) of the FOP drives inherent design tradeoffs: collection efficiency improves rapidly with a higher NA, but at the cost of resolution, increased device thickness, and fluorescence excitation efficiency. To illustrate this, we optimize two optical frontends with full-width at half maximums (FWHMs) of 8.3{\deg} and 45.7{\deg}. Implementing these designs, we show that angle-insensitivity requires filters on both sides of the FOP, due to scattering. In imaging experiments, the 520-$\mu$m-thick high-NA design is 59$\times$ more sensitive to fluorescence while only degrading resolution by 3.2$\times$. Alternatively, the low-NA design is capable of three-color fluorescence imaging with 110-$\mu$m resolution at a 1-mm working distance. Overall, we demonstrate a versatile optical frontend that is adaptable to a range of applications using different fluorophores, illumination configurations, and lensless imaging techniques.
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All authors Lukas Harris, Micah Roschelle, Jack Bartley, Mekhail Anwar
Image and Video Processing
Generative MR Multitasking with complex-harmonic cardiac encoding: Bridging the gap between gated imaging and real-time imaging
Xinguo Fang and Anthony G. Christodoulou
Purpose: To develop a unified image reconstruction framework that bridges real-time and gated cardiac MRI, including quantitative MRI. Methods: We introduce Generative Multitasking, which learns an implicit neural temporal basis from sequence timings and an interpretable latent space for cardiac and respiratory motion. Cardiac motion is modeled as a complex harmonic, with phase encoding timing and a latent amplitude capturing beat-to-beat functional variability, linking cardiac phase-resolved ("gated-like") and time-resolved ("real-time-like") views. We implemented the framework using a conditional variational autoencoder (CVAE) and evaluated it for free-breathing, non-ECG-gated radial GRE in three settings: steady-state cine imaging, multicontrast T2prep/IR imaging, and dual-flip-angle T1/T2 mapping, compared with conventional Multitasking. Results: Generative Multitasking provided flexible cardiac motion representation, enabling reconstruction of archetypal cardiac phase-resolved cines (like gating) as well as time-resolved series that reveal beat-to-beat variability (like real-time imaging). Conditioning on the previous k-space angle and modifying this term at inference removed eddy-current artifacts without globally smoothing high temporal frequencies. For quantitative mapping, Generative Multitasking reduced intraseptal T1 and T2 coefficients of variation compared with conventional Multitasking (T1: 0.13 vs. 0.31; T2: 0.12 vs. 0.32; p<0.001), indicating higher SNR. Conclusion: Generative Multitasking uses a CVAE with complex harmonic cardiac coordinates to unify gated and real-time CMR within a single free-breathing, non-ECG-gated acquisition. It allows flexible cardiac motion representation, suppresses trajectory-dependent artifacts, and improves T1 and T2 mapping, suggesting a path toward cine, multicontrast, and quantitative imaging without separate gated and real-time scans.
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