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arXiv 2025年

作者： Peng, Qingqing Liu, Yikan School of Mathematics and Statistics Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and Technology Wuhan430074 China Department of Mathematics Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto606-8502 Japan

This paper is concerned with the energy decay of a viscoelastic variable coefficient wave equation with nonlocality in time as well as nonlinear damping and polynomial nonlinear terms. Using the Lyapunov method, we establish a polynomial energy decay for the solution under relatively weak assumptions regarding the kernel of the nonlocal term. More specifically, we improve the decay rate of the energy by additionally imposing a certain convexity assumption on the kernel. Several examples are provided to confirm such improvements to faster polynomial or even exponential *** Codes 35L20, 35L70, 35B40 Copyright © 2025, The Authors. All rights reserved.

关键词： Damping

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Replace2Self: Self-Supervised Denoising based on Voxel Replacing and Image Mixing for Diffusion MRI

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IEEE Transactions on Medical Imaging 2025年 PP卷 PP页

作者： Wu, Linhai Wang, Lihui Deng, Zeyu Zhu, Yuemin Wei, Hongjiang Guizhou University Key Laboratory of Advanced Medical Imaging and Intelligent Computing of Guizhou Province Engineering Research Center of Text Computing & Cognitive Intelligence Ministry of Education State Key Laboratory of Public Big Data College of Computer Science and Technology 550025 China Univ Lyon INSA Lyon CNRS Inserm CREATIS UMR 5220 LyonF-69621 France Shanghai Jiao Tong University School of Biomedical Engineering Shanghai200030 China

Low signal to noise ratio (SNR) remains one of the limitations of diffusion weighted (DW) imaging. How to suppress the influence of noise on the subsequent analysis about the tissue microstructure is still challenging. This work proposed a novel self-supervised learning model, Replace2Self, to effectively reduce spatial correlated noise in DW images. Specifically, a voxel replacement strategy based on similar block matching in Q-space was proposed to destroy the correlations of noise in DW image along one diffusion gradient direction. To alleviate the signal gap caused by the voxel replacement, an image mixing strategy based on complementary mask was designed to generate two different noisy DW images. After that, these two noisy DW images were taken as input, and the non-correlated noisy DWimage after voxel replacement was taken as learning target, a denoising network was trained for denoising. To promote the denoising performance, a complementary mask mixing consistency loss and an inverse replacement regularization loss were also proposed. Through the comparisons against several existing DW image denoising methods on extensive simulation data with different noise distributions, noise levels and b-values, as well as the acquisition datasets and the ablation experiments, we verified the effectiveness of the proposed method. Regardless of the noise distribution and noise level, the proposed method achieved the highest PSNR, which was at least 1.9% higher than the suboptimal method when the noise level reaches 10%. Furthermore, our method has superior generalization ability due to the use of the proposed strategies. © 2025 IEEE. All rights reserved.

关键词： Signal to noise ratio

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A Hierarchical Encrypted Compression Scheme for Intra-Vehicle Network

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IEEE Transactions on Intelligent Transportation Systems 2025年

作者： Shang, Chao Cao, Jin Li, Zejian Niu, Ben Lam, Kwok-Yan Chi, Chi-Hung Li, Hui Xidian University State Key Laboratory of Integrated Services Networks School of Cyber Engineering Xi'an710126 China Nanyang Technological University College of Computing and Data Science National Digital Trust Centre Singapore639798 Singapore Chinese Academy of Sciences State Key Laboratory of Information Security Institute of Information Engineering Beijing100094 China Nanyang Technological University College of Computing and Data Science Singapore639798 Singapore Nanyang Technological University National Digital Trust Centre Singapore639798 Singapore

The CAN bus is the most widely used bus for intra-vehicle communication due to its high transmission stability, excellent real-time communication capability, and relatively low cost. As the number of ECUs grows, the CAN bus load increases and thus raises the possibility of data transmission delays and errors. Message compression based on the differential algorithm has been proposed to reduce the CAN bus load. However, current works do not consider the security problems of the CAN bus. Attackers can manage to acquire the original messages before compression and disturb the message statistics to decrease compression rate by injecting malicious frames. In this paper, we propose a secure compression mechanism for the intra-vehicle network, including an improved compression algorithm, a stream key distribution scheme, and a hierarchical encryption scheme. Formal verification results show that the proposed scheme can achieve mutual authentication, message confidentiality and integrity, resist replay attacks, and support secure compression. Evaluations using real vehicle data on 16 MHz boards show the average communication overhead can be reduced by 46.38% compared to the original messages. Performance analysis results show our scheme can reduce computational overhead on compression by 31.82% and 19.43% on decompression compared to related schemes. © 2000-2011 IEEE.

关键词： Buses

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Mapping the territories of the mountain-foothill zone of Tajikistan exposed to mudflows

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Journal of Mountain Science 2025年第1期22卷 16-30页

作者： SAFAROV Mustafo KANG Shichang FAZYLOV Ali GULAYOZOV Majid NAVRUZSHOEV Hofiz BANERJEE Abhishek MAMADJANOV Yunus Key Laboratory of Cryospheric Science and Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Research Center for Ecology and Environment of Central Asia(Dushanbe) Dushanbe 734063Tajikistan University of Chinese Academy of Sciences Beijing 100049China Institute of Water Problems Hydropower and Ecology of the National Academy of Sciences of TajikistanDushanbe 734042Tajikistan Mountain Societies Research Institute University of Central AsiaDushanbe 734000Tajikistan State Scientific Institution“Center for Research of Glaciers of the National Academy of Sciences of Tajikistan” Dushanbe 734025Tajikistan

In recent years,mudflows have emerged as a significant threat to infrastructure and lives,exhibiting increased frequency and *** study collectively addresses the rising threat of natural hazards,specifically mudflows in mountain-foothill zones in Tajikistan,utilizing UAV and remote sensing technologies to monitor their *** 2020 to 2023,we employed a QC-2 Micro UAV and a DJI Phantom 4 quadcopter to capture high-resolution aerial imagery across multiple affected districts,supplemented by pre-and post-event Sentinel-2 images analyzed using the Normalized Difference Water Index(NDWI)and Normalized Difference Vegetation Index(NDVI).Our analysis revealed that 49 districts and cities experienced significant mudflow events,resulting in estimated damages and economic losses of 30.2 million USD,with particularly severe impacts noted in the Khuroson,Tojikobod,Vakhsh,Panjakent,Lakhsh,and *** composition of mudflows in the six studied areas predominantly consisted of clay,with some regions featuring mudstone and a few exhibiting a mixture of both *** findings indicate the predominance of rain-induced mudflows in foothill areas,contrasting with rain-snow,glacial,and lake-outburst-induced mudflows in mountainous *** underscores the urgent need for effective disaster risk management strategies in vulnerable *** UAV and remote sensing technologies provides crucial information for analyzing damages,identifying vulnerable areas,and advising emergency response efforts,thereby enhancing disaster risk management in Tajikistan.

关键词： Disaster Mudflows Remote sensing Unmanned aerial vehicles Tajikistan

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Global method for monotone variational inequality problems with inequality constraints

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JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS 1997年第2期95卷 419-430页

作者： Peng, JM State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academia Sinica Beijing China

We consider optimization methods for monotone variational inequality problems with nonlinear inequality constraints. First, we study the mixed complementarity problem based on the original problem. Then, a merit function for the mixed complementarity problem is proposed, and some desirable properties of the merit function are obtained. Through the merit function, the original variational inequality problem is reformulated as simple bounded minimization. Under certain assumptions, we show that any stationary point of the optimization problem is a solution of the problem considered. Finally, we propose a descent method for the variational inequality problem and prove its global convergence.

关键词： variational inequality problems mixed complementarity problems optimization methods

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Quantum simulation of a class of highly-oscillatory transport equations via Schrödingerisation

arXiv

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arXiv 2025年

作者： Gu, Anjiao Jin, Shi School of Mathematical Sciences Shanghai Jiao Tong University Shanghai200240 China Institute of Natural Sciences Shanghai Jiao Tong University Shanghai200240 China Ministry of Education Key Laboratory in Scientific and Engineering Computing Shanghai200240 China

In this paper, we present quantum algorithms for a class of highly-oscillatory transport equations, which arise in semiclassical computation of surface hopping problems and other related non-adiabatic quantum dynamics, based on the Born-Oppenheimer approximation. Our method relies on the classical nonlinear geometric optics method, and the recently developed Schrödingerisation approach for quantum simulation of partial differential equations. The Schrödingerisation technique can transform any linear ordinary and partial differential equations into Hamiltonian systems evolving under unitary dynamics, via a warped phase transformation that maps these equations to one higher dimension. We study possible paths for better recoveries of the solution to the original problem by shifting the bad eigenvalues in the Schrödingerized system. Our method ensures the uniform error estimates independent of the wave length, thus allowing numerical accuracy, in maximum norm, even without numerically resolving the physical oscillations. Various numerical experiments are performed to demonstrate the validity of this approach. Copyright © 2025, The Authors. All rights reserved.

关键词： Eigenvalues and eigenfunctions

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Defects in lithium-ion batteries: From origins to safety risks

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Green Energy and Intelligent Transportation 2025年第3期4卷

作者： Chen, Wei Han, Xuebin Pan, Yue Yuan, Yuebo Kong, Xiangdong Liu, Lishuo Sun, Yukun Shen, Weixiang Xiong, Rui School of Mechanical Engineering Beijing Institute of Technology Beijing100081 China State Key Laboratory of Intelligent Green Vehicle and Mobility Tsinghua University Beijing100084 China School of Science Computing and Engineering Technologies Swinburne University of Technology HawthornVIC3122 Australia

Lithium-ion batteries are currently the most widely used energy storage devices due to their superior energy density, long lifespan, and high efficiency. However, the manufacturing defects, caused by production flaws and raw material impurities can accelerate battery degradation. In extreme cases, these defects may result in severe safety incidents, such as thermal runaway. Metal foreign matter is one of the main types of manufacturing defects, frequently causing internal short circuits in lithium-ion batteries. Among these, copper particles are the most common contaminants. This paper addresses the safety risks posed by manufacturing defects in lithium-ion batteries, analyzes their classification and associated hazards, and reviews the research on metal foreign matter defects, with a focus on copper particle contamination. Furthermore, we summarize the detection methods to identify defective batteries and propose future research directions to address metal foreign matter defects. © 2024 The Author(s)

关键词： Crystal impurities

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Dislocation analysis in p-type 4H-SiC: Etching morphologies and electronic properties

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Journal of Applied Physics 2025年第17期137卷

作者： Tong, Zhouyu Yang, Yanwei Huang, Yuanchao Yang, Deren Pi, Xiaodong State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and Engineering Zhejiang University Zhejiang Hangzhou310027 China Institute of Advanced Semiconductors & Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang University Zhejiang Hangzhou311215 China

As the foundational material for high-voltage n-channel Insulated Gate Bipolar Transistors (IGBTs), p-type 4H silicon carbide (4H-SiC) substrates lack comprehensive analysis of dislocations. This study extensively examines the dislocations in p-type 4H-SiC crystals grown by Physical Vapor Transport (PVT) and Top-Seeded Solution Growth (TSSG) methods using molten alkali etching technology. Optimal process parameters for etching p-type 4H-SiC wafers were identified, and different types of dislocations—threading edge dislocations (TEDs), threading screw dislocations (TSDs), and basal plane dislocations (BPDs)—were distinguished. Finally, the electronic properties of TEDs and BPDs were determined using Kelvin probe force microscopy. The study found that doping with dominant impurity Al converts deep-level TED and BPD into shallow acceptor states. This implies that Al impurities tend to occupy sites at TED and BPD dislocations, forming TED-Al4 and BPD-Al2 composite dislocations with shallow acceptor characteristics. This work not only provides guidance for molten alkali etching of p-type 4H-SiC but also enhances our understanding of the electronic behaviors of dislocations in p-type 4H-SiC. © 2025 Author(s).

关键词： Insulated gate bipolar transistors (IGBT)

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Semi-Asynchronous Federated Split Learning for computing-Limited Devices in Wireless Networks

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IEEE Transactions on Wireless Communications 2025年

作者： Ao, Huiqing Tian, Hui Ni, Wanli Nie, Gaofeng Niyato, Dusit Beijing University of Posts and Telecommunications State Key Laboratory of Networking and Switching Technology Beijing100876 China Tsinghua University Department of Electronic Engineering Beijing100084 China Nanyang Technological University College of Computing and Data Science Singapore

The rapid evolution of edge computing and artificial intelligence (AI) paves the way for pervasive intelligence in the next-generation network. As a hybrid training paradigm, federated split learning (FSL) leverages data and model parallelism to enhance training efficiency. However, existing FSL encounters unacceptable waiting latency due to device heterogeneity and synchronous model aggregation. To address this issue, we propose a semi-asynchronous FSL (SAFSL) framework that enables personalized model splitting and aperiodic model aggregation. We derive the convergence upper bound by considering factors such as the number of devices, training iterations, and data heterogeneity. To minimize the long-term average training latency while maintaining high energy efficiency in resource-constrained wireless networks, we formulate a stochastic mixed-integer nonlinear programming problem. By decomposing it into multiple sub-problems in each round, we propose a Lyapunov-based alternating optimization algorithm to solve it in an online manner. Numerical results demonstrate that our SAFSL achieves faster convergence with reduced communication overhead while maintaining high prediction performance under non-independent and identically distributed data, outperforming state-of-the-art benchmarks. Moreover, our algorithm achieves a low training latency, highlighting its superior performance and effectiveness. © 2002-2012 IEEE.

关键词： Federated learning

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Complexity of Tensor Product Functions in Representing Antisymmetry

arXiv

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arXiv 2025年

作者： Wang, Yuyang Hu, Yukuan Liu, Xin State Key Laboratory of Scientific and Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China School of Mathematical Sciences University of Chinese Academy of Sciences Beijing100049 China CERMICS Ecole des Ponts IP Paris Marne-la-Vallée77455 France

Tensor product function (TPF) approximations have been widely adopted in solving high-dimensional problems, such as partial differential equations and eigenvalue problems, achieving desirable accuracy with computational overhead that scales linearly with problem dimensions. However, recent studies have underscored the extraordinarily high computational cost of TPFs on quantum many-body problems, even for systems with as few as three particles. A key distinction in these problems is the antisymmetry requirement on the unknown functions. In the present work, we rigorously establish that the minimum number of involved terms for a class of TPFs to be exactly antisymmetric increases exponentially fast with the problem dimension. This class encompasses both traditionally discretized TPFs and the recent ones parameterized by neural networks. Our proof exploits the link between the antisymmetric TPFs in this class and the corresponding antisymmetric tensors and focuses on the Canonical Polyadic rank of the latter. As a result, our findings uncover a fundamental incompatibility between antisymmetry and low-rank TPFs in high-dimensional contexts and offer new insights for further developments. Copyright © 2025, The Authors. All rights reserved.

关键词： Tensors

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