Signal Processing
Characterizing ISCI in Multi-carrier ISAC Systems over Doubly Dispersive Channel: Joint Sensing and Communication Performance Analysis
Xuyao Yu, Zijun Gong and Zhilu Lai
This paper presents a systematic analysis of inter-symbol and inter-carrier interference (ISCI) modeling in doubly dispersive channels for integrated sensing and communication (
ISAC) systems. We propose a generalized OFDM (Weyl-Heisenberg) framework to evaluate four ISCI treatment approaches: (1) explicit estimation and compensation, (2) complete ignorance, (3) uncorrelated colored noise approximation, and (4) correlated colored noise modeling. Through continuous delay-Doppler channel characterization, we derive LMMSE channel
estimators and corresponding estimation errors (as sensing metrics) for both pilot-assisted and fully-known symbol scenarios. The communication performance is quantified via ergodic capacity bounds under imperfect CSI. Our theoretical analysis and numerical results reveal fundamental performance-complexity trade-offs, providing insights for practical
ISAC waveform and receiver design in doubly dispersive channels.
Read the full abstract ▾
Systems and Control
Steering Opinion Dynamics in Signed Time-Varying Networks via External Control Input
Swati Priya and Twinkle Tripathy
This paper studies targeted opinion formation in multi-
agent systems evolving over signed, time-varying directed graphs. The dynamics of each
agent's state follow a
Laplacian-based update rule driven by both cooperative and antagonistic interactions in the presence of exogenous factors. We formulate these exogenous factors as external control inputs and establish a suitable controller design methodology enabling collective opinion to converge to any desired steady-state configuration, superseding the natural emergent clustering or polarization behavior imposed by persistently structurally balanced influential root nodes. Our approach leverages upper Dini derivative analysis and Grönwall-type inequalities to establish exponential convergence for opinion magnitude towards the desired steady state configuration on networks with uniform quasi-strong $\delta$-connectivity. Finally, the theoretical results are validated through extensive numerical simulations.
Read the full abstract ▾
Systems and Control · Cross-listed from cs.ET
Modeling Closed-loop Analog Matrix Computing Circuits with Interconnect Resistance
Mu Zhou, Junbin Long, Yubiao Luo et al. (+1 more)
Analog
matrix computing (AMC)
circuits based on resistive random-access
memory (RRAM) have shown strong potential for accelerating
matrix operations. However, as
matrix size grows, interconnect resistance increasingly degrades computational accuracy and limits
circuit scalability. Modeling and evaluating these effects are therefore critical for developing effective mitigation strategies. Traditional SPICE (Simulation Program with Integrated
Circuit Emphasis) simulators, which rely on modified nodal analysis, become prohibitively slow for large-scale AMC
circuits due to the quadratic growth of nodes and feedback connections. In this work, we model AMC
circuits with interconnect resistance for two key operations-
matrix inversion (INV) and eigenvector computation (EGV), and propose fast solving
algorithms tailored for each case. The
algorithms exploit the sparsity of the Jacobian
matrix, enabling rapid and accurate solutions. Compared to SPICE, they achieve several orders of magnitude acceleration while maintaining high accuracy. We further extend the approach to open-loop
matrix-vector multiplication (MVM)
circuits, demonstrating similar efficiency gains. Finally, leveraging these fast solvers, we develop a bias-based compensation strategy that reduces interconnect-induced errors by over 50% for INV and 70% for EGV
circuits. It also reveals the scaling behavior of the optimal bias with respect to
matrix size and interconnect resistance.
Read the full abstract ▾
All authors Mu Zhou, Junbin Long, Yubiao Luo, Zhong Sun
Signal Processing
Mip-NeWRF: Enhanced Wireless Radiance Field with Hybrid Encoding for Channel Prediction
Yulin Fu, Jiancun Fan, Shiyu Zhai et al. (+2 more)
Recent work on wireless radiance fields represents a promising deep learning approach for channel prediction, however, in complex environments these methods still exhibit limited robustness, slow convergence, and modest accuracy due to insufficiently refined modeling. To address this issue, we propose Mip-NeWRF, a physics-informed neural framework for accurate indoor channel prediction based on sparse channel measurements. The framework operates in a ray-based pipeline with coarse-to-fine importance sampling: frustum samples are encoded, processed by a shared multilayer perceptron (MLP), and the outputs are synthesized into the channel frequency response (CFR). Prior to MLP input, Mip-NeWRF performs conical-frustum sampling and applies a scale-consistent hybrid positional encoding to each frustum. The scale-consistent normalization aligns positional encodings across scene scales, while the hybrid encoding supplies both scale-robust, low-frequency stability to accelerate convergence and fine spatial detail to improve accuracy. During training, a curriculum learning schedule is applied to stabilize and accelerate convergence of the shared MLP. During channel synthesis, the MLP outputs, including predicted virtual transmitter presence probabilities and amplitudes, are combined with modeled pathloss and surface interaction attenuation to enhance physical fidelity and further improve accuracy. Simulation results demonstrate the effectiveness of the proposed approach: in typical scenarios, the normalized mean square error (NMSE) is reduced by 14.3 dB versus state-of-the-art baselines.
Read the full abstract ▾
All authors Yulin Fu, Jiancun Fan, Shiyu Zhai, Zhibo Duan, Jie Luo
Signal Processing
LMMSE-Optimal Pilot Pattern Design Based on Covariance Matrix Approximation for OFDM Channel Estimation in Doubly Dispersive Channel
Xuyao Yu, Zijun Gong and Zhilu Lai
This paper investigates the optimal pilot pattern design, in the linear minimum mean square error (LMMSE)
estimator sense, for OFDM systems in doubly dispersive channels. To enable analytical tractability, the channel covariance
matrix is decomposed into the Kronecker product of two Hermitian Toeplitz
matrices corresponding to the delay and Doppler domains. By invoking the Szegö limit
theorem, these
matrices are shown to be approximately diagonalizable by discrete
Fourier transform (DFT)
matrices. Based on this structure, the LMMSE channel estimation error is reformulated into a compact analytical form, from which a closed-form lower bound is derived. Furthermore, we establish the condition under which this bound is achieved by a
lattice-based pilot pattern. Numerical results verify that the proposed
matrix approximation introduces negligible error and examples of the proposed
lattice design are given.
Read the full abstract ▾
Signal Processing
xHAP: Cross-Modal Attention for Haptic Feedback Estimation in the Tactile Internet
Georgios Kokkinis, Alexandros Iosifidis and Qi Zhang
The Tactile Internet requires ultra-low latency and high-fidelity haptic feedback to enable immersive teleoperation. A key challenge is to ensure ultra-reliable and low-latency transmission of haptic packets under channel variations and potential network outages. To address these issues, one approach relies on local estimation of haptic feedback at the operator side. However, designing an accurate
estimator that can faithfully reproduce the true haptic forces remains a significant challenge. In this paper, we propose a novel deep learning architecture, xHAP, based on cross-modal
attention to estimate haptic feedback. xHAP fuses information from two distinct data streams: the teleoperator's historical force feedback and the operator's control action sequence. We employ modality-specific encoders to learn temporal representations, followed by a cross-
attention layer where the teleoperator haptic data attend to the operator input. This fusion allows the model to selectively focus on the most relevant operator sensory data when predicting the teleoperator's haptic feedback. The proposed architecture reduces the mean-squared error by more than two orders of magnitude compared to existing methods and lowers the SNR requirement for reliable transmission by $10~\mathrm{dB}$ at an error threshold of $0.1$ in a 3GPP UMa scenario. Additionally, it increases coverage by $138\%$ and supports $59.6\%$ more haptic users even under 10 dB lower SNR compared to the baseline.
Read the full abstract ▾
Systems and Control
Context-Aware Management of IoT Nodes: Balancing Informational Value with Energy Usage
Nihal Ahmad, Talha Manzoor and Ijaz Haider Naqvi
The operational lifetime of energy-harvesting wireless sensor nodes is limited by availability of the energy source and the capacity of the installed energy buffer. When a sensor node depletes its energy reserves, manual intervention is often required to resume node operation. While lowering the duty cycle would help extend the network lifetime, this is often undesirable, especially in time-critical applications, where rapid collection and dissemination of information is vital. In this paper, we propose a context-aware energy management policy that helps balance the two opposing objectives of timely data collection and dissemination with energy conservation. We capture these objectives through the Value of Information (VoI) of observations made by a sensor node and the State of Energy (SoE) of the energy buffer. We formulate the energy management policy as a Model Predictive Control (MPC) problem which computes device sampling and transmission frequencies to maximize a defined utility criterion over a finite, receding, time-horizon. In the process, we also develop a unique mathematical representation for VoI, that adequately captures aspects related to continuity in monitoring, urgency of dissemination, and representation of the phenomena being observed. In the end, we use data collected from a real-world flash flood event, to evaluate our decision framework across multiple scenarios of energy availability.
Read the full abstract ▾
Systems and Control
Unifying Sequential Quadratic Programming and Linear-Parameter-Varying Algorithms for Real-Time Model Predictive Control
Kristóf Floch, Amon Lahr, Roland Tóth et al. (+1 more)
This paper presents a unified framework that connects sequential quadratic programming (SQP) and the iterative linear-parameter-varying model predictive control (LPV-MPC) technique. Using the differential formulation of the LPV-MPC, we demonstrate how SQP and LPV-MPC can be unified through a specific choice of scheduling variable and the 2nd Fundamental
Theorem of Calculus (FTC)
embedding technique and compare their convergence properties. This enables the unification of the zero-order approach of SQP with the LPV-MPC scheduling technique to enhance the computational efficiency of robust and
stochastic MPC problems. To demonstrate our findings, we compare the two schemes in a simulation example. Finally, we present real-time feasibility and performance of the zero-order LPV-MPC approach by applying it to Gaussian process (GP)-based MPC for autonomous racing with real-world experiments.
Read the full abstract ▾
All authors Kristóf Floch, Amon Lahr, Roland Tóth, Melanie N. Zeilinger
Systems and Control
RIS-based Communication Enhancement and Location Privacy Protection in UAV Networks
Ziqi Chen, Jun Du, Chunxiao Jiang et al. (+2 more)
With the explosive advancement of unmanned aerial vehicles (
UAVs), the security of efficient
UAV networks has become increasingly critical. Owing to the open nature of its communication environment, illegitimate malicious
UAVs (MUs) can infer the position of the source
UAV (SU) by analyzing received signals, thus compromising the SU location
privacy. To protect the SU location
privacy while ensuring efficient communication with legitimate receiving
UAVs (RUs), we propose an Active Reconfigurable Intelligent Surface (ARIS)-assisted covert communication scheme based on virtual partitioning and artificial noise (AN). Specifically, we design a novel ARIS architecture integrated with an AN module. This architecture dynamically partitions its reflecting elements into multiple sub-regions: one subset is optimized to enhance the communication rate between the SU and RUs, while the other subset generates AN to interfere with the localization of the SU by MUs. We first derive the Cramér-Rao Lower Bound (CRLB) for the localization with received signal strength (RSS), based on which, we establish a joint optimization framework for communication enhancement and localization interference. Subsequently, we derive and validate the optimal ARIS partitioning and power allocation under average channel conditions. Finally, tailored optimization methods are proposed for the reflection precoding and AN design of the two partitions. Simulation results validate that, compared to baseline schemes, the proposed scheme significantly increases the localization error of the SU by MUs while maintaining efficient communication between the SU and RUs, thereby effectively protecting the SU location
privacy.
Read the full abstract ▾
All authors Ziqi Chen, Jun Du, Chunxiao Jiang, Tony Q. S. Quek, Zhu Han
Audio and Speech Processing · Cross-listed from cs.SD
Diff-V2M: A Hierarchical Conditional Diffusion Model with Explicit Rhythmic Modeling for Video-to-Music Generation
Shulei Ji, Zihao Wang, Jiaxing Yu et al. (+4 more)
Video-to-music (V2M) generation aims to create music that aligns with visual content. However, two main challenges persist in existing methods: (1) the lack of explicit rhythm modeling hinders audiovisual temporal
alignments; (2) effectively integrating various visual features to condition music generation remains non-trivial. To address these issues, we propose Diff-V2M, a general V2M framework based on a hierarchical conditional
diffusion model, comprising two core components: visual feature extraction and conditional music generation. For rhythm modeling, we begin by evaluating several rhythmic representations, including low-resolution mel-spectrograms, tempograms, and onset detection functions (ODF), and devise a rhythmic predictor to infer them directly from
videos. To ensure contextual and affective coherence, we also extract semantic and emotional features. All features are incorporated into the generator via a hierarchical cross-
attention mechanism, where emotional features shape the affective tone via the first layer, while semantic and rhythmic features are fused in the second cross-
attention layer. To enhance feature integration, we introduce timestep-aware fusion strategies, including feature-wise linear modulation (FiLM) and weighted fusion, allowing the model to adaptively balance semantic and rhythmic cues throughout the
diffusion process. Extensive experiments identify low-resolution ODF as a more effective signal for modeling musical rhythm and demonstrate that Diff-V2M outperforms existing models on both in-domain and out-of-domain
datasets, achieving state-of-the-art performance in terms of objective metrics and subjective comparisons. Demo and code are available at https://Tayjsl97.github.io/Diff-V2M-Demo/.
Read the full abstract ▾
All authors Shulei Ji, Zihao Wang, Jiaxing Yu, Xiangyuan Yang, Shuyu Li, Songruoyao Wu, Kejun Zhang
Audio and Speech Processing
Towards Effective and Efficient Non-autoregressive decoders for Conformer and LLM-based ASR using Block-based Attention Mask
Tianzi Wang, Xurong Xie, Zengrui Jin et al. (+9 more)
Automatic
speech recognition (ASR) systems often rely on autoregressive (AR)
Transformer decoder architectures, which limit efficient inference parallelization due to their sequential nature. To this end, non-autoregressive (NAR) approaches aim primarily to achieve significant decoding speedup while the maintaining recognition accuracy that is comparable to AR baselines. This paper proposes a novel NAR block-based
attention mask decoder (AMD) that effectively improves decoding efficiency while maintaining ASR accuracy, and also offering flexibility in balancing the performance-efficiency trade-off on both Conformer and large
language model (LLM)-based ASR systems. The proposed AMD performs parallel inference within contiguous blocks of output labels while maintaining monotonic left-to-right prediction between blocks. A one-pass beam search
algorithm is designed to dynamically fuse Connectionist Temporal Classification (CTC), AR decoder, and AMD probabilities. Experiments are conducted on normal
speech LS960 and DBank elderly
speech across: a) The Conformer encoder-decoder ASR system with filterbank input features; b) its integration with WavLM features; and c) further advancement by integrating an LLM-based decoder. On the LS960 task, the proposed AMD empowered tripartite decoder achieves decoding speedup ratios of up to 1.44x, 1.55x, and 2.31x under the three model configurations over the CTC + AR baselines, without statistically significant WER increases. When operating with real-time factors (RTFs) comparable to the baselines, the tripartite decoder produces statistically significant WER reductions of 0.19%, 0.62% and 0.13% absolute (4.3%, 16.3%, and 3.8% relative). Similar improvements are also obtained on the DBank task.
Read the full abstract ▾
All authors Tianzi Wang, Xurong Xie, Zengrui Jin, Mengzhe Geng, Jiajun Deng, Zhaoqing Li, Shoukang Hu, Shujie Hu, Guinan Li, Mingyu Cui, Helen Meng, Xunying Liu
Signal Processing
VAE-Based Synthetic EMG Generation with Mix-Consistency Loss for Recognizing Unseen Motion Combinations
Itsuki Yazawa and Akira Furui
Electromyogram (EMG)-based motion classification using machine learning has been widely employed in applications such as prosthesis control. While previous studies have explored generating synthetic patterns of combined motions to reduce training data requirements, these methods assume that combined motions can be represented as linear combinations of basic motions. However, this assumption often fails due to complex neuromuscular phenomena such as muscle co-contraction, resulting in low-fidelity synthetic signals and degraded classification performance. To address this limitation, we propose a novel method that learns to synthesize combined motion patterns in a structured latent space. Specifically, we employ a variational autoencoder (VAE) to encode EMG signals into a low-dimensional representation and introduce a mixconsistency loss that structures the latent space such that combined motions are embedded between their constituent basic motions. Synthetic patterns are then generated within this structured latent space and used to train classifiers for recognizing unseen combined motions. We validated our approach through upper-limb motion classification experiments with eight healthy participants. The results demonstrate that our method outperforms input-space synthesis approaches, achieving approximately 30% improvement in accuracy.
Read the full abstract ▾
Signal Processing
RadHARSimulator V2: Video to Doppler Generator
Weicheng Gao
Radar-based human activity recognition (HAR) still lacks a comprehensive simulation method. Existing software is developed based on models or motion-captured data, resulting in limited flexibility. To address this issue, a simulator that directly generates Doppler spectra from recorded
video footage (RadHARSimulator V2) is presented in this paper. Both computer
vision and radar modules are included in the simulator. In computer
vision module, the real-time model for object detection with global nearest neighbor is first used to detect and track human targets in the
video. Then, the high-resolution network is used to estimate two-dimensional poses of the detected human targets. Next, the three-dimensional poses of the detected human targets are obtained by nearest matching method. Finally, smooth temporal three-dimensional pose estimation is achieved through Kalman filtering. In radar module, pose interpolation and smoothing are first achieved through the Savitzky-Golay method. Second, the delay model and the mirror method are used to simulate echoes in both free-space and through-the-wall scenarios. Then, range-time map is generated using pulse compression, moving target indication, and DnCNN. Next, Doppler-time map (DTM) is generated using short-time
Fourier transform and DnCNN again. Finally, the ridge features on the DTM are extracted using the maximum local energy method. In addition, a hybrid parallel-serial neural network architecture is proposed for radar-based HAR. Numerical experiments are conducted and analyzed to demonstrate the effectiveness of the designed simulator and the proposed network model. The open-source code of this work can be found in: https://github.com/JoeyBGOfficial/RadHARSimulatorV2-
Video-to-Doppler-Generator.
Read the full abstract ▾
Systems and Control
Assumed Density Filtering and Smoothing with Neural Network Surrogate Models
Simon Kuang and Xinfan Lin
The Kalman filter and Rauch-Tung-Striebel (RTS) smoother are optimal for state estimation in linear dynamic systems. With nonlinear systems, the challenge consists in how to propagate uncertainty through the state transitions and output function. For the case of a neural network model, we enable accurate uncertainty propagation using a recent state-of-the-art analytic formula for computing the mean and covariance of a deep neural network with Gaussian input. We argue that cross
entropy is a more appropriate performance metric than RMSE for evaluating the accuracy of filters and smoothers. We demonstrate the superiority of our method for state estimation on a
stochastic Lorenz system and a Wiener system, and find that our method enables more optimal linear quadratic regulation when the state estimate is used for feedback. Code available at https: //github.com/simontheflutist/analytic-moments.
Read the full abstract ▾
Signal Processing
Linear-Bias Time Encoding for Low-Rate Quantized Representation of Bandlimited Signals
Anshu Arora, Kaluguri Yashaswini and Satish Mulleti
Integrate-and-fire time encoding machines (IF-TEMs) provide an efficient framework for asynchronous sampling of bandlimited signals through discrete firing times. However, conventional IF-TEMs often exhibit excessive oversampling, leading to inefficient encoding for signals with smoothly distributed information. This letter introduces a linear-bias IF-TEM (LB-IF-TEM), where the bias dynamically tracks the input signal to maintain a nearly constant integrator input, thereby localizing the firing intervals. The resulting concentrated distribution enables effective non-uniform quantization with reduced distortion. Theoretical analysis establishes explicit bounds on the achievable oversampling range, while experimental results demonstrate that the proposed method attains comparable reconstruction accuracy at significantly lower bitrate than existing IF-TEM variants. The LB-IF-TEM thus provides a low-power, communication-efficient, and analytically tractable framework for time-based signal encoding and reconstruction.
Read the full abstract ▾
Systems and Control · Cross-listed from cs.DC
Distribution and Management of Datacenter Load Decoupling
Liuzixuan Lin and Andrew A. Chien
The exploding power consumption of AI and cloud datacenters (DCs) intensifies the long-standing concerns about their carbon footprint, especially because DCs' need for constant power clashes with volatile renewable generation needed for grid decarbonization. DC flexibility (a.k.a. load adaptation) is a key to reducing DC carbon emissions by improving grid renewable absorption. DC flexibility can be created, without disturbing datacenter capacity by decoupling a datacenter's power capacity and grid load with a collection of energy resources. Because decoupling can be costly, we study how to best distribute and manage decoupling to maximize benefits for all. Key considerations include site variation and datacenter-grid cooperation. We first define and compute the power and energy needs of datacenter load decoupling, and then we evaluate designed distribution and management approaches. Evaluation shows that optimized distribution can deliver >98% of the potential grid carbon reduction with 70% of the total decoupling need. For management, DC-grid cooperation (2-way sharing and control vs. 1-way info sharing) enables 1.4x grid carbon reduction. Finally, we show that decoupling may be economically viable, as on average datacenters can get power cost and carbon emissions benefits greater than their local costs of decoupling. However, skew across sites suggests grid intervention may be required.
Read the full abstract ▾
Systems and Control
Validating Warehouse Picking Strategies Using Simulation: Case Study of a Plumbing Equipment Firm
Phattara Khumprom, Wanatchapong Kongkaew, Antoun Yaacoub et al. (+1 more)
In today competitive business environment, efficient logistics are essential, especially in industries where timely delivery matters. This research aims to improve warehouse picking cycle time through simulation-based analysis, using a leading plumbing equipment distributor in Thailand as a case study. The study identifies inefficiencies such as disorganized storage and poor placement of high-frequency items that slow down picking. To address this, an optimized storage approach using ABC analysis is proposed, prioritizing high-demand items near the entrance. Three storage policies-Fixed, Random, and Combination (Fixed Zone)-are tested with a Zone Picking strategy through simulation to identify the most efficient picking routes. The findings provide insights for improving warehouse layout and inventory placement to enhance overall performance.
Read the full abstract ▾
All authors Phattara Khumprom, Wanatchapong Kongkaew, Antoun Yaacoub, Nattakit Thanawitsatien
Image and Video Processing
ROI-based Deep Image Compression with Implicit Bit Allocation
Kai Hu, Han Wang, Renhe Liu et al. (+3 more)
Region of Interest (ROI)-based image compression has rapidly developed due to its ability to maintain high fidelity in important regions while reducing data redundancy. However, existing compression methods primarily apply masks to suppress background information before quantization. This explicit bit allocation strategy, which uses hard gating, significantly impacts the statistical distribution of the
entropy model, thereby limiting the coding performance of the compression model. In response, this work proposes an efficient ROI-based deep image compression model with implicit bit allocation. To better utilize ROI masks for implicit bit allocation, this paper proposes a novel Mask-Guided Feature Enhancement (MGFE) module, comprising a Region-Adaptive
Attention (RAA) block and a Frequency-Spatial Collaborative
Attention (FSCA) block. This module allows for flexible bit allocation across different regions while enhancing global and local features through frequencyspatial domain collaboration. Additionally, we use dual decoders to separately reconstruct foreground and background images, enabling the coding network to optimally balance foreground enhancement and background quality preservation in a datadriven manner. To the best of our knowledge, this is the first work to utilize implicit bit allocation for high-quality regionadaptive coding. Experiments on the COCO2017
dataset show that our implicit-based image compression method significantly outperforms explicit bit allocation approaches in rate-distortion performance, achieving optimal results while maintaining satisfactory visual quality in the reconstructed background regions.
Read the full abstract ▾
All authors Kai Hu, Han Wang, Renhe Liu, Zhilin Li, Shenghui Song, Yu Liu
Signal Processing
OG-PCL: Efficient Sparse Point Cloud Processing for Human Activity Recognition
Jiuqi Yan, Chendong Xu and Dongyu Liu
Human activity recognition (HAR) with millimeter-wave (mmWave) radar offers a
privacy-preserving and robust alternative to camera- and wearable-based approaches. In this work, we propose the Occupancy-Gated Parallel-CNN Bi-LSTM (OG-PCL) network to process sparse 3D radar point clouds produced by mmWave sensing. Designed for lightweight deployment, the parameter size of the proposed OG-PCL is only 0.83M and achieves 91.75 accuracy on the RadHAR
dataset, outperforming those existing baselines such as 2D CNN, PointNet, and 3D CNN methods. We validate the advantages of the tri-view parallel structure in preserving spatial information across three dimensions while maintaining efficiency through ablation studies. We further introduce the Occupancy-Gated Convolution (OGConv) block and demonstrate the necessity of its occupancy compensation mechanism for handling sparse point clouds. The proposed OG-PCL thus offers a compact yet accurate framework for real-time radar-based HAR on lightweight platforms.
Read the full abstract ▾
Systems and Control
An Improved Dual-Attention Transformer-LSTM for Small-Sample Prediction of Modal Frequency and Actual Anchor Radius in Micro Hemispherical Resonator Design
Yuyi Yao, Gongliu Yang, Runzhuo Xu et al. (+2 more)
The high-temperature glassblowing-fabricated micro hemispherical resonator (MHR) exhibits high
symmetry and high Q-value for precision inertial
navigation. However, MHR design entails a comprehensive evaluation of multiple possible configurations and demands extremely time-consuming simulation of key parameters combination. To address this problem, this paper proposed a rapid prediction method of modal frequency and actual anchor radius of designed MHR using an improved
Transformer-LSTM (Long Short-Term
Memory) model for rapid design sizing. High-temperature-induced softening deformation at the anchor point reduces the actual anchor radius below the designed value. By varying key parameters such as resonator height, anchor radius and edge thickness, finite element glassblowing simulation and modal analyse were conducted to obtain the first six modal frequencies and actual anchor radius. To address regression prediction challenges with limited data, dual multi-head self-
attention (MHSA) mechanisms replaced the
transformer's standard Feed Forward Network, to improve hidden information capture for high-accuracy predictions of modal frequencies and anchor radius. By checking fabricating feasibility of anchor radius and allowing rapid modal characteristics evaluation without interference, ablation and comparative experiments validated the method's superiority, as an effective support of MHR design. Design optimization experiments demonstrate a prediction accuracy of 96.35%, with computational time reduced to 1/48,000 of traditional finite element methods, significantly improving design efficiency. This study offers a new paradigm for intelligent Micro-Electro-Mechanical System (MEMS) device design under complex process conditions.
Read the full abstract ▾
All authors Yuyi Yao, Gongliu Yang, Runzhuo Xu, Yongqiang Tu, Haozhou Mo
Image and Video Processing · Cross-listed from cs.LG
Rethinking Graph Super-resolution: Dual Frameworks for Topological Fidelity
Pragya Singh and Islem Rekik
Graph super-resolution, the task of inferring high-resolution (HR) graphs from low-resolution (LR) counterparts, is an underexplored yet crucial research direction that circumvents the need for costly data acquisition. This makes it especially desirable for resource-constrained fields such as the medical domain. While recent GNN-based approaches show promise, they suffer from two key limitations: (1)
matrix-based node super-resolution that disregards graph structure and lacks permutation invariance; and (2) reliance on node representations to infer edge weights, which limits scalability and expressivity. In this work, we propose two GNN-agnostic frameworks to address these issues. First, Bi-SR introduces a bipartite graph connecting LR and HR nodes to enable structure-aware node super-resolution that preserves
topology and permutation invariance. Second, DEFEND learns edge representations by mapping HR edges to nodes of a dual graph, allowing edge inference via standard node-based GNNs. We evaluate both frameworks on a real-world
brain connectome
dataset, where they achieve state-of-the-art performance across seven topological measures. To support generalization, we introduce twelve new simulated
datasets that capture diverse
topologies and LR-HR relationships. These enable comprehensive benchmarking of graph super-resolution methods.
Read the full abstract ▾
Signal Processing
DRL-Based Beam Positioning for LEO Satellite Constellations with Weighted Least Squares
Po-Heng Chou, Chiapin Wang, Kuan-Hao Chen et al. (+1 more)
This paper investigates a lightweight deep reinforcement learning (DRL)-assisted weighting framework for CSI-free multi-satellite positioning in LEO constellations, where each visible satellite provides one serving beam (one pilot response) per epoch. A discrete-action Deep Q-Network (DQN) learns satellite weights directly from received pilot measurements and
geometric features, while an augmented weighted least squares (WLS)
estimator provides physics-consistent localization and jointly estimates the receiver clock bias. The proposed hybrid design targets an accuracy-runtime trade-off rather than absolute supervised optimality. In a representative 2-D setting with 10 visible satellites, the proposed approach achieves sub-meter accuracy (0.395m RMSE) with low computational overhead, supporting practical deployment for resource-constrained LEO payloads.
Read the full abstract ▾
All authors Po-Heng Chou, Chiapin Wang, Kuan-Hao Chen, Wei-Chen Hsiao
Signal Processing · Cross-listed from cs.NI
Measurement-Driven Early Warning for Resilient 5G NSA Railway Networks
Po-Heng Chou, Da-Chih Lin, Hung-Yu Wei et al. (+2 more)
This paper presents a measurement-driven study of early warning for reliability breakdown events in 5G non-standalone (NSA) railway networks. Using 10 Hz metro-train measurement traces with serving- and neighbor-
cell indicators, we
benchmark six representative learning models, including CNN, LSTM, XGBoost, Anomaly
Transformer, PatchTST, and TimesNet, under multiple observation windows and prediction horizons. Rather than proposing a new prediction architecture, this study develops a measurement-driven
benchmark to quantify the feasibility and operating trade-offs of seconds-ahead reliability prediction in 5G NSA railway environments. Experimental results show that learning models can anticipate
radio link failure (RLF)-related reliability breakdown events seconds in advance using lightweight
radio features available on commercial devices. The presented
benchmark provides insights for sensing-assisted communication control and offers an empirical foundation for integrating sensing and analytics into future mobility control.
Read the full abstract ▾
All authors Po-Heng Chou, Da-Chih Lin, Hung-Yu Wei, Walid Saad, Yu Tsao