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Delay Minimization for NOMA-MEC Offloading in ABS-Aided Maritime Communication Networks

IEEE Transactions on Vehicular technology 2025年第6期74卷 9577-9590页

作者： He, Yixin Huang, Fanghui Wang, Dawei Yang, Lina Zhang, Ruonan Jiaxing University College of Information Science and Engineering Provincial Key Laboratory of Multimodal Perceiving and Intelligent Systems Jiaxing314001 China Jiaxing University College of Artificial Intelligence Jiaxing314001 China Jiaxing Key Laboratory of Smart Transportations Jiaxing314001 China Northwestern Polytechnical University School of Electronics and Information Xi'an710072 China Jiaxing University College of Information Science and Engineering Jiaxing314001 China

As maritime activities increase, the demand for high-speed, low-latency communications and efficient task processing in maritime communication networks (MCNets) intensifies. Currently, sea-surface communications and tasks mainly depend on on-shore base stations, which have limited coverage, and marine satellites, which offer broader reach but cannot provide high-speed connections and are costly. Motivated by the above, we investigate the deployment of air base stations (ABSs) in MCNets to offer flexible coverage and handle maritime-specific tasks. ABS-aided MCNets benefit from the integration of mobile edge computing (MEC) and non-orthogonal multiple access (NOMA) techniques. Specifically, by optimizing the task offloading and resource allocation, we formulate a total task processing delay minimization problem under the constraints of task time-to-live (TTL) and successive interference cancellation (SIC) decoding threshold. Since the formulated problem is non-convex, we decouple it and solve it iteratively. The channel allocation, power control, offloading ratio, and computation resource allocation are tackled in turn. Simulation results demonstrate that the proposed scheme significantly outperforms existing schemes in reducing the total task processing delay. Notably, the incorporation of NOMA markedly enhances the task offloading rate, further decreasing the total task processing delay. The proposed scheme cuts the total task processing delay by at least 7.7% compared to the state-of-the-art schemes and by 40.9% against the local computing benchmark. Additionally, the performance of the proposed scheme, including its complexity, convergence, and the performance loss due to iterative optimization, is analyzed. © 1967-2012 IEEE.

关键词： Marine communication

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Low Loss and Low EMI Noise Trench IGBT with Shallow Emitter Trench Controlled P-Type Dummy Region

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Chinese Journal of Electronics 2024年第2期33卷 326-335页

作者： Jinping ZHANG Xiaofeng LI Rongrong ZHU Kang WANG Bo ZHANG State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China (UESTC) Institute of Electronic and Information Engineering of UESTC in Guangdong

A novel trench insulated gate bipolar transistor（TIGBT） with a shallow emitter trench controlled P-type dummy region（STCP-TIGBT） is *** with the conventional TIGBT with floating P-type dummy region（CFP-TIGBT） and TIGBT with floating P-type dummy region and normally on hole path（HFPTIGBT）,the proposed STCP structure not only speeds up the extraction of excessive holes in the turn-off process but also reduces the Miller plateau charge(Qgc).Therefore,both the power loss and electromagnetic interference（EMI） noise are significantly *** results show that the Qgcof the proposed device is only 501 nC/cm2,which is reduced by 58.5% and 26.4% when compared to the CFP-TIGBT and HFP-TIGBT,*** same on-state voltage drop(Vceon) of 1.02 V,the turn-off loss(Eoff) of the proposed device is 13.49 mJ/cm2,which is 64.6%and 67.6% less than those of the CFP-TIGBT and HFP-TIGBT,***,the reverse recovery dVak/dt of the freewheeling diode at same turn-on loss(Eon) of 31.8 mJ/cm2for the proposed STCP-TIGBT is only 2.15 kV/μs,which is reduced by 91.3% and 57.2% when compared to 24.69 kV/μs and 5.02 kV/μs for the CFP-TIGBT and HFPTIGBT,*** reduced dV/dt significantly suppresses the electromagnetic interference noise generated by the proposed device.

关键词： Trench insulated gate bipolar transistor On-state voltage drop Turn-off loss Turn-on loss Electromagnetic interference noise Shallow emitter trench P-type dummy region

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OCDM with Index Modulation for Autonomous Underwater Vehicles Communication

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-16页

作者： Jia, Zhenyu Zhang, Rongxin Chen, Zhong Yuan, Fei Key Laboratory of Underwater Acoustic Communication and Marine Information Technology Xiamen University Xiamen China School of Electronic Science and Engineering Xiamen University Xiamen China

Autonomous underwater vehicles (AUVs) equipped with acoustic modems are currently one of the important means of obtaining underwater environment data such as sounds and images. They rely on high-speed underwater acoustic (UWA) communication technology for data transmission tasks. Orthogonal chirp division multiplexing (OCDM) is a multicarrier method based on chirp spread spectrum (CSS) which has better reliability in frequency selective fading channels than orthogonal frequency division multiplexing (OFDM). In this work, we combine index modulation (IM) and propose an OCDM-IM system that provides faster data rates when it activates the same number of subchirps as OCDM. On the other hand, it activates fewer subchirps when the data rate is the same, so it has better anti-interference capability. The simulation results under a measured UWA channel and random channels and the experimental results show that OCDM-IM has a better bit-error rate (BER) performance than that of OCDM and OFDM-IM systems when the subchirps are not fully loaded. In particular, when a small number of subchirps are activated, OCDM-IM is able to provide up to 2x bit rate with more than 5 dB improvement in BER performance. Our simulation and experimental results also show that IM has much better reliability than constellation mapping when Doppler effect is considered. Therefore, OCDM-IM is more suitable for the communication of AUVs. IEEE

关键词： Peak to average power ratio

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Underwater acoustic metamaterials

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National science Review 2023年第6期10卷 258-280页

作者： Erqian Dong Peizheng Cao Jinhu Zhang Sai Zhang Nicholas X.Fang Yu Zhang Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education College of Ocean and Earth Sciences Xiamen University State Key Laboratory of Marine Environmental Science Xiamen University School of Physics and Electronic Engineering Jiangsu University Department of Mechanical Engineering Massachusetts Institute of Technology

Acoustic metamaterials have been widely investigated over the past few decades and have realized acoustic parameters that are not achievable using conventional *** demonstrating that locally resonant acoustic metamaterials are capable of acting as subwavelength unit cells,researchers have evaluated the possibility of breaking the classical limitations of the material mass density and bulk *** with theoretical analysis,additive manufacturing and engineering applications,acoustic metamaterials have demonstrated extraordinary capabilities,including negative refraction,cloaking,beam formation and super-resolution *** to the complexity of impedance boundaries and mode transitions,there are still challenges in freely manipulating acoustic propagation in an underwater *** review summarizes the developments in underwater acoustic metamaterials over the past 20 years,which include underwater acoustic invisibility cloaking,underwater beam formation,underwater metasurfaces and phase engineering,underwater topological acoustics and underwater acoustic metamaterial *** the evolution of underwater metamaterials and the timeline of scientific advances,underwater acoustic metamaterials have demonstrated exciting applications in underwater resource development,target recognition,imaging,noise reduction,navigation and communication.

关键词： underwater acoustic metamaterials invisibility cloaking beam formation topological acoustics metasurfaces absorbers

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Underwater images enhancement using contrast limited adaptive parameter settings histogram equalization

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Multimedia Tools and Applications 2024年 1-15页

作者： Chen, Yahui Liang, Yitao College of Information Science and Engineering Henan University of Technology Henan Zhengzhou China Henan Key Laboratory of Grain Photoelectric Detection and Control Henan Zhengzhou China

CLAHE is widely used in underwater image processing because of its excellent performance in contrast enhancement. The selection of the clip point formula is the core problem of the CLAHE methods, and the selection of suitable clipping value has become the focus of some extended methods. In this paper, an automatic CLAHE underwater image enhancement algorithm is proposed. The method determines the clipping value according to the high-order moment dynamic features of each block of the underwater image. By quantifying the dynamic features of each block in the image more precisely, and then adding it to the clipping value formula, the contrast and details of the underwater image can be effectively enhanced. In order to effectively improve the saturation and brightness of underwater images, this paper chooses a more accurate and intuitive HSV model. Experimental results show that our methods enhance the contrast subjectively, while suppressing the amplification of noise very well, and also increase the saturation of underwater images. In objective metrics, our method obtains the best values in underwater quality assessment (UIQM), SSIM, and PSNR. © The Author(s), under exclusive licence to Springer science+Business Media, LLC, part of Springer Nature 2024.

关键词： Underwater imaging

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Contour-Guided 3-D Sensing and Localization With mmWave Radar for Infrastructure-Assisted Autonomous Vehicles

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IEEE Internet of Things Journal 2025年第12期12卷 20056-20070页

作者： Deng, Kaikai Xing, Ling Wu, Honghai Ma, Huahong Gao, Jianping Ling, Yue Henan University of Science and Technology School of Information Engineering Luoyang471023 China Henan University of Science and Technology College of Vehicle and Traffic Engineering Luoyang471023 China Beijing University of Posts and Telecommunications State Key Laboratory of Network and Switching Technology Beijing100876 China

Infrastructure-assisted autonomous driving has become a new paradigm that enables autonomous vehicles to fuse sensor data and improve driving safety, where a key enabling technology for achieving this vision is to real-time and accurate registering 3-D mmWave radar point clouds between the infrastructure and the vehicle. To this end, we propose Artemis, a novel lightweight system capable of achieving real-time registration with decimeter-level localization. Artemis consists of three components: 1) a modal association-based salient object extraction component leverages the complementary advantages of cameras and radars to extract semantics and areas of salient objects for radar point clouds;2) a salient object shape construction component extracts the shape contour of salient objects based on their inherent geometries;and 3) a contour-guided 3-D point cloud registration component combines two key strategies, keypoint matching strategy and early exit strategy, to quickly select keypoints and transformation directions for achieving accurate registration in real-time. We implement and evaluate Artemis with two multiview datasets collected in the CARLA platform and campus. The experiment results show that Artemis achieves an average registration error of 0.33 m within 32.26 ms. © 2014 IEEE.

关键词： Autonomous vehicles

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Lewis base multisite ligand engineering in efficient and stable perovskite solar cells

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Journal of Energy Chemistry 2024年第12期99卷 277-291页

作者： Danqing Ma Dongmei He Qing Zhu Xinxing Liu Yue Yu Xuxia Shai Zhengfu Zhang Sam Zhang Jing Feng Jianhong Yi Jiangzhao Chen Key Laboratory of Optoelectronic Technology&Systems(Ministry of Education) College of Optoelectronic EngineeringChongqing UniversityChongqing 400044China Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Institute of Physical and Engineering Science/Faculty of Science Kunming University of Science and TechnologyKunming 650500YunnanChina School of Aeronautics Harbin Institute of TechnologyHarbin 150001HeilongjiangChina HIT Zhengzhou Research Institute Zhengzhou 450000HenanChina

Perovskite solar cells(PSCs) have stood out from many photovoltaic technologies due to their flexibility,cost-effectiveness and high-power conversion efficiency(PCE). Nevertheless, the further development of PSCs is greatly hindered by the trap-induced non-radiative recombination losses and poor long-term work stability. In the past decade, the huge advancements have been obtained on suppressing nonradiative recombination and enhancing device durability. Among them, the multisite ligands(MSLs) engineering plays a crucial role in precise control and directional modification of functional layers and interfaces,which contributes to markedly increased PCE and lifetimes of PSCs. In view of this, this review summarizes the advances of MSLs in PSCs. From the perspective of functional groups and chemical interaction,the modulation mechanisms of properties of different functional layers and interfaces and device performance via various MSLs are deeply investigated and revealed. Finally, the prospects for the application and development direction of MSLs in PSCs are legitimately proposed.

关键词： Perovskite solar cells Multisite ligands Defect passivation Ion migration suppression Stability

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Polyphonic sound event localization and detection based on Multiple Attention Fusion ResNet

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Mathematical Biosciences and engineering 2024年第2期21卷 2004-2023页

作者： Zhang, Shouming Zhang, Yaling Liao, Yixiao Pang, Kunkun Wan, Zhiyong Zhou, Songbin Faculty of Information Engineering and Automation Kunming University of Science and Technology Kunming650500 China Institute of Intelligent Manufacturing Guangdong Academy of Science Guangdong Key Laboratory of Modern Control Technology Guangzhou510030 China

Sound event localization and detection have been applied in various fields. Due to the polyphony and noise interference, it becomes challenging to accurately predict the sound event and their occurrence locations. Aiming at this problem, we propose a Multiple Attention Fusion ResNet, which uses ResNet34 as the base network. Given the situation that the sound duration is not fixed, and there are multiple polyphonic and noise, we introduce the Gated Channel Transform to enhance the residual basic block. This enables the model to capture contextual information, evaluate channel weights, and reduce the interference caused by polyphony and noise. Furthermore, Split Attention is introduced to the model for capturing cross-channel information, which enhances the ability to distinguish the polyphony. Finally, Coordinate Attention is introduced to the model so that the model can focus on both the channel information and spatial location information of sound events. Experiments were conducted on two different datasets, TAU-NIGENS Spatial Sound Events 2020, and TAU-NIGENS Spatial Sound Events 2021. The results demonstrate that the proposed model significantly outperforms state-of-the-art methods under multiple polyphonic and noise-directional interference environments and it achieves competitive performance under a single polyphonic environment. ©2024 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution License.

关键词： Deep learning

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Structure evolution andτ_(f)influence mechanism of Bi_(1-x)Ho_(x)VO_(4)microwave dielectric ceramics for LTCC applications

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Journal of Materials science & technology 2024年第30期197卷 1-8页

作者： Huaicheng Xiang Yuheng Zhang Junqi Chen Yang Zhou Ying Tang Jinwu Chen Liang Fang Key Laboratory of Low-Dimensional Structural Physics and Application Education Department of Guangxi Zhuang Autonomous RegionCollege of Physics and Electronic Information EngineeringGuilin University of TechnologyGuilin541004China Guangxi Universities Key Laboratory of Non-Ferrous Metal Oxide Electronic Functional Materials and Devices Guangxi Key Laboratory of Optical and Electronic Materials and DevicesCollege of Materials Science and EngineeringGuilin University of TechnologyGuilin541004China School of Mechanical Engineering Guilin University of Aerospace TechnologyGuilin541004China

Bi_(1-x)Ho_(x)VO_(4)(0.1≤x≤0.9)ceramics were prepared via a solid-state reaction method,and all the ceram-ics could be well densified in the 920–980℃*** ceramics with 0.1≤x<0.4 were composed of both monoclinic scheelite(M)and tetragonal zircon(T)phases,and a single M phase could be obtained in the range of x≥*** measuredε_(r) decreased from 58.9(x=0.1)to 14.7(x=0.9),so do the calcu-lated values(ε_(r)(C−M)=34.3–12.1),and the main reason forε_(r)>ε_(r)(C−M)was the rattling of Ho^(3+)in the *** points with zeroτf appeared in Bi1–x Hox VO4(0≤x≤1)ceramics,and the best mi-crowave dielectric properties withε_(r)=16.6,Q×f=18,400 GHz(f=10.69 GHz),andτf=+3.29 ppm/℃were obtained in the Bi_(0.2)Ho_(0.8)VO_(4)*** change in temperature coefficient of ionic polarizability(τ_(αm))caused by the rattling effect of cations is the physical essence that affectsτ***,the rattling effect can be used as an effective mechanism to regulateτf in low-ε_(r) ***,there was no chemical reaction between Bi_(1-x)Ho_(x)VO_(4) and Ag electrode,which indicates potential applications in low-temperature co-fired ceramic(LTCC)technology.

关键词： Bi_(1–x)Ho_(x)VO_(4) Near-zeroτ_(f) Bond valence Rattling effect LTCC

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Dynamic Visual Semantic Sub-Embeddings and Fast Re-Ranking for Image-Text Retrieval

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IEEE Transactions on Multimedia 2025年 27卷 3781-3796页

作者： Wei, Wenzhang Gui, Zhipeng Wu, Changguang Zhao, Anqi Peng, Dehua Wu, Huayi Wuhan University School of Remote Sensing and Information Engineering Wuhan430079 China Wuhan University State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Collaborative Innovation Center of Geospatial Technology Wuhan430079 China Nanjing University of Science and Technology School of Computer Science and Engineering Nanjing210094 China

The core of image-text retrieval is to accurately measure the similarity between different modalities in a unified representation space. However, compared to textual descriptions of a certain perspective, the visual modality has more semantic variations. Therefore, images are usually associated with multiple textual captions in databases. Although popular symmetric embedding methods have explored numerous modal interaction approaches, they often learn toward outputting the average representation of multiple semantic variations within image embeddings. Consequently, information entropy in embeddings is increased, resulting in redundancy and decreased accuracy. In this work, we propose a Dynamic Visual Semantic SubEmbeddings framework (DVSE) to reduce the information entropy. Specifically, we obtain a set of heterogeneous visual sub-embeddings through dynamic orthogonal constraint loss. To encourage the generated candidate image embeddings to capture various semantic variations, we construct a mixed distribution and employ a variance-aware weighting loss to assign different weights to the optimization process. In addition, we develop a Fast Re-ranking strategy (FR) to efficiently evaluate the retrieval results and enhance the *** compare the performance with existing set-based method using five image feature encoders and three text feature encoders on three benchmark datasets: MSCOCO, Flickr30K and CUB Captions. We also show the role of different components by ablation studies and perform a sensitivity analysis of the hyperparameters. The qualitative analysis of visualized bidirectional retrieval and attention maps further demonstrates the ability of our method to encode semantic variations. © 1999-2012 IEEE.

关键词： Sensitivity analysis

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