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Clock Bias Gross Error Detection Method Based on WS-MAD

Gyroscopy and Navigation 2024年第1期15卷 68-82页

作者： Jia Su Gao, Mengjia Yi, Qingwu Wang, Binbin Ma, Zhiwei College of Information Science and Engineering Hebei University of Science and Technology Shijiazhuang China State Key Laboratory of Satellite Navigation System and Equipment Technology Shijiazhuang China Henan University of Economics and Law Zhengzhou China

Abstract: This paper proposes a clock bias gross error detection method, which combines weighted support vector data description (SVDD) with modified median absolute deviation (MAD) to address the limitations of the traditional MAD method. The method uses the local reachable density as the weighting factor of SVDD, which fully considers the local characteristics of each data. By constructing the minimum hypersphere in the high-dimensional feature space, the one-dimensional data are transformed into the distance from the vector point to the center of the hypersphere in the high-dimensional space. This transformation increases the discrepancy between normal data and gross errors. The modified MAD method probes the distance from the current epoch vector point to the center of the hypersphere for gross errors, and thus determines whether the current clock bias is a gross error. The precision clock bias data of BDS-3 with different sampling intervals provided by GFZ were used for simulation experiments. By comparing the results of the MAD method and the WS-MAD method, it is found that the WS-MAD method can detect the small gross errors in the smooth clock bias frequency data and more gross errors in the clock bias data with trend term floating. The fitting and prediction analyses on satellites with different orbits and clock types show that the WS-MAD method improves the fitting and prediction accuracy of MEO and IGSO satellites better than that of GEO satellites. For the same MEO satellites, the enhancement effect of hydrogen clocks is better than that of rubidium clocks. © Pleiades Publishing, Ltd. 2024.

关键词： Vector spaces

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UAV-Aided Multi-antenna Relay systems with Wireless Power Transfer for Maritime Communications 14th

UAV-Aided Multi-antenna Relay Systems with Wireless Power T...

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14th EAI International Conference on Wireless and Satellite systems, WiSATS 2024

作者： Li, Yuheng Zhou, Zhiquan Wang, Jinlong Wang, Lina Wang, Chenxu School of Information Science and Engineering Harbin Institute of Technology Weihai264209 China Shandong Provincial Key Laboratory of Marine Electronic Information and Intelligent Unmanned Systems Weihai264209 China Key Laboratory of Cross-Domain Synergy and Comprehensive Support for Unmanned Marine Systems Ministry of Industry and Information Technology Weihai264209 China

ISBN: (纸本)9783031862021

With the increase in maritime activities, traditional communication methods can no longer meet the needs of today’s maritime work, and the use of unmanned aerial vehicle(UAV) relay communications in marine scenarios has attracted more and more attention. In this paper, A long-distance three-node two-hop UAV relay system for maritime users is investigated. The UAV aerial relay node first transmits an energy-carrying radio frequency (RF) signal to the maritime user node, which then harvests energy and sends data information back to the UAV aerial relay node, which in turn forwards it to the land node. Considering the peculiarities of maritime communication channels, a novel land-air-maritime communication channel model is proposed. Utilizing Zero-Forcing/Zero-Transmission (ZFR/ZFT) technology, a precoding matrix for the aerial relay node is designed, followed by simulation and emulation, the performance of the channel is tested in the case of different transmission power of relay nodes or different number of antennas of relay nodes. © ICST Institute for Computer sciences, Social Informatics and Telecommunications engineering 2025.

关键词： Unmanned aerial vehicles (UAV)

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Flat Zn deposition at battery anode via an ultrathin robust interlayer

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Nano Research 2024年第9期17卷 8104-8111页

作者： Yizhou Wang Jianyu Chen Zibo Chen Qian He Zhengnan Tian Jin Zhao Yanwen Ma Husam N.Alshareef Materials Science and Engineering King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia State Key Laboratory of Organic Electronics and Information Displays(KLOEID)and Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Nanjing University of Posts and TelecommunicationsNanjing 210023China Suzhou Vocational Institute of Industrial Technology Suzhou 215104China

Rechargeable aqueous zinc(Zn)ion batteries(AZIBs)using low-cost and safe Zn metal anodes are considered promising candidates for future grid-scale energy storage systems,but the Zn dendrite problem severely hinders the further prospects of *** Zn depositing behaviors toward horizontal alignment is highly effective and thus has received huge ***,such a strategy is usually based on previous substrate engineering,which requires complex preparation or expensive ***,it is essential to develop a novel solution that can realize horizontally aligned Zn flake deposition via easy operation and low ***,we report an ultrathin and robust Kevlar membrane as the interlayer to mechanically suppress Zn dendrite *** to the randomly distributed flaky dendrites in the control group,the deposited Zn sheets would grow into parallel alignment with the existence of such *** the dendrites are effectively suppressed,Zn||Cu asymmetric,Zn||Zn symmetric,and Zn||MnO_(2)full batteries using Kevlar interlayer deliver significantly improved cycling ***,the Zn||MnO_(2)pouch cell using a Kevlar interlayer delivers stable cycling performance and shows stable operation during multi-angle *** believe this work provides a new possibility for regulating Zn deposition from a crystallographic perspective.

关键词： Zn metal anodes Zn dendrites aqueous Zn ion batteries dendrite suppression (002)crystal plane

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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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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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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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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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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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High-temperature oxidation resistance of Si-coated C/SiC composites

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Rare Metals 2024年第9期43卷 4566-4572页

作者： Jie Xiao Hua-Yue Zhang Sheng-Kai Gong Hui-Bin Xu Hong-Bo Guo School of Materials Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structure Materials and Protective Coatings(Ministry of Industry and Information Technology) Beihang UniversityBeijing 100191China

In this paper,Si coatings were sprayed onto C/SiC composite substrates by atmospheric plasma spraying(APS).The high-temperature oxidation behavior of the substrate and coating at temperatures of 1100 and 1300℃was also *** C/SiC ceramic matrix composite will be damaged seriously and even failed due to the oxidation of carbon fibers in *** Si coating effectively improved the oxidation resistance of the C/SiC substrate in the high-temperature oxidation *** effect of the thickness of the Si coatings on the oxidation resistance was *** 150-μm coating is proved to enable the substrate to have the lowest oxidation weight loss and the best oxidation resistance after static oxidation for 5 h.

关键词： Ceramic matrix composites(CMCs) Carbon fiber Si coating Oxidation Plasma spray

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A survey for light field super-resolution

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High-Confidence Computing 2024年第1期4卷 118-129页

作者： Mingyuan Zhao Hao Sheng Da Yang Sizhe Wang Ruixuan Cong Zhenglong Cui Rongshan Chen Tun Wang Shuai Wang Yang Huang Jiahao Shen State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang UniversityBeijing 100191China Key Laboratory of Data Science and Intelligent Computing International Innovation InstituteBeihang UniversityHangzhou 311115China State Key Laboratory of Software Development Environment School of Computer Science and EngineeringBeihang UniversityBeijing 100191China

Compared to 2D imaging data,the 4D light field(LF)data retains richer scene’s structure information,which can significantly improve the computer’s perception capability,including depth estimation,semantic segmentation,and LF ***,there is a contradiction between spatial and angular resolution during the LF image acquisition *** overcome the above problem,researchers have gradually focused on the light field super-resolution(LFSR).In the traditional solutions,researchers achieved the LFSR based on various optimization frameworks,such as Bayesian and Gaussian *** learning-based methods are more popular than conventional methods because they have better performance and more robust generalization *** this paper,the present approach can mainly divided into conventional methods and deep learning-based *** discuss these two branches in light field spatial super-resolution(LFSSR),light field angular super-resolution(LFASR),and light field spatial and angular super-resolution(LFSASR),***,this paper also introduces the primary public datasets and analyzes the performance of the prevalent approaches on these ***,we discuss the potential innovations of the LFSR to propose the progress of our research field.

关键词： Light field super-resolution Convolutional neural network Transformer Sub-aperture image Epipolar-plane image

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