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arXiv 2025年

作者： Sun, He Zhu, Lipeng Mei, Weidong Zhang, Rui Department of Electrical and Computer Engineering National University of Singapore Singapore117583 Singapore National Key Laboratory of Wireless Communications University of Electronic Science and Technology of China 611731 China School of Science and Engineering Shenzhen Research Institute of Big Data The Chinese University of Hong Kong Guangdong Shenzhen518172 China

Channel state information (CSI) is essential to the performance optimization of intelligent reflecting surface (IRS)aided wireless communication systems. However, the passive and frequency-flat reflection of IRS, as well as the high-dimensional IRS-reflected channels, have posed practical challenges for efficient IRS channel estimation, especially in wideband communication systems with significant multi-path channel delay spread. To tackle the above challenge, we propose a novel neural network (NN)-empowered IRS channel estimation and passive reflection design framework for the wideband orthogonal frequency division multiplexing (OFDM) communication system based only on the user’s reference signal received power (RSRP) measurements with time-varying random IRS training reflections. As RSRP is readily accessible in existing communication systems, our proposed channel estimation method does not require additional pilot transmission in IRS-aided wideband communication systems. In particular, we show that the average received signal power over all OFDM subcarriers at the user terminal can be represented as the prediction of a single-layer NN composed of multiple subnetworks with the same structure, such that the autocorrelation matrix of the wideband IRS channel can be recovered as their weights via supervised learning. To exploit the potential sparsity of the channel autocorrelation matrix, a progressive training method is proposed by gradually increasing the number of subnetworks until a desired accuracy is achieved, thus reducing the training complexity. Based on the estimates of IRS channel autocorrelation matrix, the IRS passive reflection is then optimized to maximize the average channel power gain over all subcarriers. Numerical results indicate the effectiveness of the proposed IRS channel autocorrelation matrix estimation and passive reflection design under wideband channels, which can achieve significant performance improvement compared to the existing IRS ref

关键词： Orthogonal frequency division multiplexing

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How Much Reserve Fuel: Quantifying the Maximal Energy Cost of System Disturbances

How Much Reserve Fuel: Quantifying the Maximal Energy Cost o...

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IEEE Conference on Decision and Control

作者： Ram Padmanabhan Craig Bakker Siddharth Abhijit Dinkar Melkior Ornik Department of Electrical and Computer Engineering University of Illinois Urbana-Champaign Urbana IL USA Coordinated Science Laboratory University of Illinois UrbanaChampaign Urbana IL USA National Security Directorate Pacific Northwest National Laboratory Richland WA USA Department of Aerospace Engineering University of Illinois UrbanaChampaign Urbana IL USA

ISBN: (数字)9798350316339

ISBN: (纸本)9798350316346

Motivated by the design question of additional fuel needed to complete a task in an uncertain environment, this paper introduces metrics to quantify the maximal additional energy used by a control system in the presence of bounded disturbances when compared to a nominal, disturbance-free system. In particular, we consider the task of finite-time stabilization for a linear time-invariant system. We first derive the nominal energy required to achieve this task in a disturbance-free system, and then the worst-case energy over all feasible disturbances. The latter leads to an optimal control problem with a least-squares solution, and then an infinited-imensional optimization problem where we derive an upper bound on the solution. The comparison of these energies is accomplished using additive and multiplicative metrics, and we derive analytical bounds on these metrics. Simulation examples on an ADMIRE fighter jet model demonstrate the practicability of these metrics, and their variation with the task hardness, a combination of the distance of the initial condition from the origin and the task completion time.

关键词： Measurement Upper bound Costs Additives Optimal control Fuels Optimization

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Cross-Modal Few-Shot Learning with Second-Order Neural Ordinary Differential Equations

arXiv

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arXiv 2024年

作者： Zhang, Yi Cheng, Chun-Wun He, Junyi He, Zhihai Schönlieb, Carola-Bibiane Chen, Yuyan Aviles-Rivero, Angelica I. Harbin Institute of Technology China Department of Electrical and Electronic Engineering Southern University of Science and Technology China Department of Applied Mathematics and Theoretical Physics University of Cambridge United Kingdom Pengcheng Laboratory China Shanghai Key Laboratory of Data Science School of Computer Science Fudan University China Yau Mathematical Sciences Center Tsinghua University China

We introduce SONO, a novel method leveraging Second-Order Neural Ordinary Differential Equations (Second-Order NODEs) to enhance cross-modal few-shot learning. By employing a simple yet effective architecture consisting of a Second-Order NODEs model paired with a cross-modal classifier, SONO addresses the significant challenge of overfitting, which is common in few-shot scenarios due to limited training examples. Our second-order approach can approximate a broader class of functions, enhancing the model’s expressive power and feature generalization capabilities. We initialize our cross-modal classifier with text embeddings derived from class-relevant prompts, streamlining training efficiency by avoiding the need for frequent text encoder processing. Additionally, we utilize text-based image augmentation, exploiting CLIP’s robust image-text correlation to enrich training data significantly. Extensive experiments across multiple datasets demonstrate that SONO outperforms existing state-of-the-art methods in few-shot learning performance. Copyright © 2024, The Authors. All rights reserved.

关键词： Zero-shot learning

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Prediction of Stroke Risk Within 7-Years Follow Up Using Machine Learning Models

Prediction of Stroke Risk Within 7-Years Follow Up Using Mac...

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2023 IEEE EMBS Special Topic Conference on Data science and engineering in Healthcare, Medicine and Biology, IEEECONF 2023

作者： Tsarapatsani, Konstantina-Helen Sakellarios, Antonis Tsakanikas, Vasilis D. Rudolf, Henrik Trampisch, Hans J. Pezoulas, Vasileios C. Matsopoulos, George K. Fotiadis, Dimitrios I. University of Ioannina Unit of Medical Technology and Intelligent Information Systems Dept. of Materials Science and Engineering IoanninaGR 45110 Greece Biomedical Research Institute Greece Institute for Biostatistics and Informatics in Medicine and Ageing Research University Medical Center Rostock Germany Ruhr University Bochum Department of Medical Informatics Biometry and Epidemiology Bochum Germany National Technical University of Athens School of Electrical and Computer Engineering Athens Greece

ISBN: (纸本)9798350383386

A stroke, also known as brain attack, occurs when blood supply to your brain is interrupted. Primary prevention relies on prompt prediction of a stroke. While currently there are several clinical risk scores, machine learning (ML) models seems to be more suitable tools for accurate prediction of stroke events. Therefore, this work focuses on the prediction of stroke within 7 years follow-up in patients who have not suffered from a stroke or TIA event at baseline. LightGBM (LGBM), Extreme Grading Boosting (XGBoost), Support Vector Machine (SVM) and Decision Tree were employed in the getABI dataset, which includes 5,897 participants. The performance of models was calculated by Accuracy (ACC), Sensitivity (SENS), Specificity (SPE) and area under the receiver operating characteristic curve (AUC) of each model. According to the comparison analysis's results, LGBM has been shown to be the most trustworthy algorithm, with accuracy 68 %. Moreover, sex, age, status of peripheral artery disease (PAD), history of myocardial infarction, angina pectoris, amputation and diabetes and pulse status of different arteries can be used as a simple and cost-effective way to predict *** Relevance: A fatal medical emergency, stroke may be anticipated using artificial intelligence, and the sooner it is predicted, the more cerebrovascular disease occurrences can be avoided. © 2023 IEEE.

关键词： Forecasting

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Robust Phase Retrieval from Quantized and Noisy Measurements

Robust Phase Retrieval from Quantized and Noisy Measurements

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Acoustics, Speech, and Signal Processing Workshops (ICASSPW), IEEE International Conference on

作者： Yihong Gao Luteng Zhu Zhuoyang An Mingjie Shao Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong SAR China School of Information Science and Engineering Shandong University Qingdao China Computer School Beijing Information Science and Technology University Beijing China Key Laboratory of System and Control AMSS Chinese Academy of Sciences Beijing China

ISBN: (数字)9798331519315

ISBN: (纸本)9798331519322

The phase retrieval (PR) problem involves recovering a signal from amplitude-only measurements and has been extensively studied in various physical measurement and signal processing systems. Recently, there has been increasing interest in the quantized phase retrieval (QPR) problem, where the observed amplitude is quantized to binary values. The existing studies have focused on the noiseless case. In this paper, we address a robust QPR problem that accounts for both quantization and noise. We formulate the robust QPR problem using maximum-likelihood estimation (MLE), which results in a non-convex and challenging optimization problem due to the complexity of its likelihood function. To obtain a high-quality solution, we develop an expectation-maximization (EM) algorithm combined with the Wirtinger flow, allowing us to convert the problem into a more manageable form at each iteration. Our method is implemented on both randomly generated synthetic data and image reconstruction tasks. The results demonstrate that our approach significantly enhances signal recovery performance under the combined effects of quantization and noise. Additionally, the proposed method exhibits better runtime efficiency compared to existing approaches.

关键词： Maximum likelihood estimation Phase measurement Quantization (signal) Runtime Noise Signal processing algorithms Noise measurement Speech processing Optimization Synthetic data

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Energy-Efficient Probabilistic Semantic Communication over Space-Air-Ground Integrated Networks

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IEEE Transactions on Wireless Communications 2025年

作者： Zhao, Zhouxiang Yang, Zhaohui Chen, Mingzhe Zhu, Chen Xu, Wei Zhang, Zhaoyang Huang, Kaibin Zhejiang University College of Information Science and Electronic Engineering China Zhejiang Provincial Key Laboratory of Info. Proc. Commun Hangzhou310027 China University of Miami Department of Electrical and Computer Engineering Institute for Data Science and Computing Coral GablesFL33146 United States Zhejiang University Polytechnic Institute Hangzhou310015 China Hangzhou Dianzi University School of Communication Engineering Hangzhou310018 China Southeast University National Mobile Communications Research Laboratory Nanjing211189 China The University of Hong Kong Department of Electrical and Electronic Engineering Hong Kong

Space-air-ground integrated networks (SAGINs) are emerging as a pivotal element in the evolution of future wireless networks. Despite their potential, the joint design of communication and computation within SAGINs remains a formidable challenge. In this paper, the problem of energy efficiency in SAGIN-enabled probabilistic semantic communication (PSCom) system is investigated. In the considered model, a satellite needs to transmit data to multiple ground terminals (GTs) via an unmanned aerial vehicle (UAV) acting as a relay. During transmission, the satellite and the UAV can use PSCom technique to compress the transmitting data, while the GTs can automatically recover the missing information. The PSCom is underpinned by shared probabilistic graphs that serve as a common knowledge base among the transceivers, allowing for resource-saving communication at the expense of increased computation resource. Through analysis, the computation overhead function in PSCom is a piecewise function with respect to the semantic compression ratio. Therefore, it is important to make a balance between communication and computation to achieve optimal energy efficiency. The joint communication and computation problem is formulated as an optimization problem aiming to minimize the total communication and computation energy consumption of the network under latency, power, computation capacity, bandwidth, semantic compression ratio, and UAV location constraints. To solve this non-convex non-smooth problem, we propose an iterative algorithm where the closed-form solutions for computation capacity allocation and UAV altitude are obtained at each iteration. Numerical results show the effectiveness of the proposed algorithm. © 2002-2012 IEEE.

关键词： Drones

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EpiTESTER: Testing Autonomous Vehicles with Epigenetic Algorithm and Attention Mechanism

arXiv

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arXiv 2023年

作者： Lu, Chengjie Ali, Shaukat Yue, Tao The Department of Engineering Complex Software Systems Simula Research Laboratory Oslo0258 Norway Simula Research Laboratory Norway Oslo Metropolitan University Oslo0258 Norway The School of Computer Science and Engineering Beihang University Beijing100191 China

Testing autonomous vehicles (AVs) under various environmental scenarios that lead the vehicles to unsafe situations is known to be challenging. Given the infinite possible environmental scenarios, it is essential to find critical scenarios efficiently. To this end, we propose a novel testing method, named EpiTESTER, by taking inspiration from epigenetics, which enables species to adapt to sudden environmental changes. In particular, EpiTESTER adopts gene silencing as its epigenetic mechanism, which regulates gene expression to prevent the expression of a certain gene, and the probability of gene expression is dynamically computed as the environment changes. Given different data modalities (e.g., images, lidar point clouds) in the context of AV, EpiTESTER benefits from a multi-model fusion transformer to extract high-level feature representations from environmental factors and then calculates probabilities based on these features with the attention mechanism. To assess the cost-effectiveness of EpiTESTER, we compare it with a classical genetic algorithm (GA) (i.e., without any epigenetic mechanism implemented) and EpiTESTER with equal probability for each gene. We evaluate EpiTESTER with four initial environments from CARLA, an open-source simulator for autonomous driving research, and an end-to-end AV controller, Interfuser. Our results show that EpiTESTER achieved a promising performance in identifying critical scenarios compared to the baselines, showing that applying epigenetic mechanisms is a good option for solving practical problems. © 2023, CC BY.

关键词： Autonomous vehicles

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Wireless 6G Connectivity for Massive Number of Devices and Critical Services

arXiv

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arXiv 2024年

作者： Kalør, Anders E. Durisi, Giuseppe Coleri, Sinem Parkvall, Stefan Yu, Wei Mueller, Andreas Popovski, Petar The Department of Information and Computer Science Keio University Yokohama223-8522 Japan The Department of Electronic Systems Aalborg University Aalborg9220 Denmark The Department of Electrical Engineering Chalmers University of Technology Gothenburg412 96 Sweden The Department of Electrical and Electronics Engineering Koç University Istanbul34450 Turkey Ericsson Research Stockholm164 83 Sweden The Edward S. Rogers Sr. Department of Electrical and Computer Engineering University of Toronto TorontoONM5S 3G4 Canada Robert Bosch GmbH Stuttgart70465 Germany

Compared to the generations up to 4G, whose main focus was on broadband and coverage aspects, 5G has expanded the scope of wireless cellular systems towards embracing two new types of connectivity: massive machine-type communication (mMTC) and ultra-reliable low-latency communications (URLLC). This paper discusses the possible evolution of these two types of connectivity within the umbrella of 6G wireless systems. The paper consists of three parts. The first part deals with the connectivity for a massive number of devices. While mMTC research in 5G predominantly focuses on the problem of uncoordinated access in the uplink for a large number of devices, the traffic patterns in 6G may become more symmetric, leading to closed-loop massive connectivity. One of the drivers for this type of traffic patterns is distributed/decentralized learning and inference. The second part of the paper discusses the evolution of wireless connectivity for critical services. While latency and reliability are tightly coupled in 5G, 6G will support a variety of safety critical control applications with different types of timing requirements, as evidenced by the emergence of metrics related to information freshness and information value. Additionally, ensuring ultra-high reliability for safety critical control applications requires modeling and estimation of the tail statistics of the wireless channel, queue length, and delay. The fulfillment of these stringent requirements calls for the development of novel AI-based techniques, incorporating optimization theory, explainable AI, generative AI and digital twins. The third part analyzes the coexistence of massive connectivity and critical services. Specifically, we consider scenarios in which a massive number of devices need to support traffic patterns of mixed criticality. This is followed by a discussion about the management of wireless resources shared by services with different criticality. Copyright © 2024, The Authors. All rights reserve

关键词： 5G mobile communication systems

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Bilateral Teleoperation Control Using Unified Interactive Model for Manipulation in Contact Environment*

Bilateral Teleoperation Control Using Unified Interactive Mo...

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IEEE International Conference on Robotics and Biomimetics

作者： Xiao Yang Fanghao Huang Jason Gu Zheng Chen State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University Hangzhou China Ocean College Zhejiang University Zhoushan China Department of Electrical and Computer Engineering Dalhousie University Halifax Canada Zhejiang Laboratory Hangzhou China

In this paper, a novel bilateral teleoperation control is designed specifically for manipulation in contact environment. Firstly, serval interaction conditions (e.g., free motion and rigid interaction) are defined and unified into one equation as the designed unified interactive model, which can also be utilized as a control objective. Based on this model, a remote hybrid motion/force controller is designed for remote robot, which achieves the good position and force tracking, and ensures the precise and safe contact force that helps reduce the workload of operator. Subsequently, the contact force is reconstructed in the local side by estimating and transmitting the non-power environment coefficient from remote side, which provides the operator with accurate force feedback. Since the coefficient replaces the direct transmission of force signal in the communication channel, the traditional power-cycle problem is essentially avoided, which guarantees the stability of teleoperation system under communication time delays. Comparative experiments are implemented to verify the effectiveness of proposed method for teleoperated manipulation.

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A Novel Design of Capacitive Plasmonic Near Field Transducer

arXiv

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arXiv 2024年

作者： Du, Tianxiang Laughlin, David E. Zhu, Jian-Gang Data Storage Systems Center Carnegie Mellon University PittsburghPA15213 United States Department of Materials Science and Engineering Carnegie Mellon University PittsburghPA15213 United States Department of Electrical and Computer Engineering Carnegie Mellon University PittsburghPA15213 United States

A near field transducer (NFT) is a key photonics component in heat assisted magnetic recording (HAMR) for the localized heating of the magnetic medium. In this work, we present a novel NFT design through capacitive coupling. In our design, tapered metal bars separated by thin dielectric materials with gap distance G are used to create the plasmonic resonance and focus the electromagnetic field. The design is motivated by the intention to improve thermal stability, which can be achieved through segmentation using thermally stable dielectric material between the plasmonic metal bars. Using COMSOL Multiphysics software, the performance of this capacitive-coupled NFT is systematically modeled. It is shown that the electromagnetic field could gradually be focused through the tapering towards the air bearing surface (ABS). In addition, the focusing effect could be enhanced with a smaller NFT peg size at the resonant wavelength. The material selection for the NFT tip material will be discussed to further address the thermal stability of the device. In conclusion, this capacitive-coupled NFT with dielectric separation gaps and tapering yields an enhanced |E| field intensity at the tip with the potential for an enhanced material thermal stability. Such a design can also exhibit applications in other energy delivery systems as well as plasmonic waveguides and sensors. © 2024, CC BY.

关键词： Multiphysics

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