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Cross-domain intelligent cooperative spectrum sensing algorithm based on Federated Learning and Swin-Transformer neural network

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Engineering Applications of Artificial Intelligence 2025年 157卷

作者： Lingwei Xu Zhihe Gao Yufang Li T. Aaron Gulliver Department of Information Science and Technology Qingdao University of Science & Technology Qingdao 266061 China Key Laboratory of Industrial Internet of Things & Networked Control Ministry of Education Chongqing University of Posts and Telecommunications Chongqing 400065 China Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle Hubei University of Arts and Science Xiangyang 441053 Hubei China Guangxi Key Laboratory of Hybrid Computation and IC Design Analysis(Guangxi Minzu University) Nanning 530006 China Department of Electrical and Computer Engineering University of Victoria Victoria BC V8W 2Y2 Canada

The deployment of 6th Generation (6G) mobile networks will bring revolutionary changes to organizations and users through higher speeds, lower latency, and more intelligent network management. This will require more efficient spectrum sharing to improve network performance. Cognitive Radio (CR) can be employed to help achieve this goal. However, data collection at the fusion center for cooperative spectrum sensing (CSS) creates a risk of sensing user (SU) data leakage. In this paper, an intelligent CSS algorithm for mobile communication is proposed based on Federated Learning with a Swin-Transformer. First, to achieve the cross-domain process, a Continuous Wavelet Transform (CWT) is used with the normalized time series data to obtain a time-frequency spectrum map with joint time-frequency features. Second, Federated Learning is employed to realize distributed CSS to reduce sensing overhead, improve the security of sensing data, and eliminate the SU data isolation with traditional distributed CSS. Then, a new Swin-Transformer spectrum sensing is proposed for fusion learning of the time-frequency spectrum map. The fusion of Federated Learning and Swin-Transformer neural network provides cooperation with multiple SUs to achieve efficient spectrum sensing using the K -rank fusion criterion. Compared with the Convolutional Neural Network (CNN), ViT-Transformer, Graph Neural Network (GNN) and EfficientNet algorithms, the detection probability of the proposed algorithm has increased by 45 %, and the false alarm probability has decreased by 13 %.

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Research on Transforming Effect and Calculation Method of MMC Converter on AC / DC Harmonics

Research on Transforming Effect and Calculation Method of MM...

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Sustainable Power and Energy Conference (iSPEC)

作者： Liu Cui Guangqiang Peng Jingsong He Jiyang Wu Chizu Mao Ning Jiao State Key Laboratory of HVDC Electric Power Research Institute China Southern Power Grid GuangZhou China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System GuangZhou China CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid GuangZhou China Maintenance & Test Center EHV Power Transmission Company Guangzhou CSGKEY LABORATORY FOR DC TRANSMISSIONEQUIPMENT STATE EVALUATION AND FAULT DIAGNOSIS GuangZhou China College of Electrical Engineering and Information Technology Sichuan University Chengdu China

ISBN: (纸本)9781665414401

Modular multilevel converter (MMC) is currently the most concerned voltage source converter topology in the field of flexible direct current transmission (VSC-HVDC). Due to its non-linear characteristics, harmonic components will inevitably be generated in AC and DC systems, which may affect the operation of equipment and system, cause protection equipment to malfunction, and cause interference to neighboring communications. The MMC converter is a non-linear device, which can be considered as an amplifying modulator with voltage and current conversion functions. The AC and DC networks are coupled to each other through the MMC converter to generate dynamic harmonic interaction. In recent years, harmonic instability problems have appeared in many VSC-HVDC projects. Compared with other converter topologies, the transfer relationship of harmonics on the AC and DC sides of MMC converters has not been studied in depth. In this paper, by studying the AC/DC harmonic conversion characteristics of MMC converters, it reveals the conversion law of MMC converters between AC/DC harmonics; through theoretical derivation, the quantitative calculation method of MMC harmonic transmission process is given. PSCAD simulation results prove the correctness of the above results.

关键词： Network topology Simulation Bridge circuits Voltage Power system harmonics Harmonic analysis Frequency conversion

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Experimental Study on Acoustic Attenuation of Bubble Wake

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IOP Conference Series: Materials Science and Engineering 2020年第6期780卷

作者： Jing Han Shuai Lv Zhongpeng Wu Mingwei Zhang Jin Bai Science and Technology on Underwater Test and Control Laboratory Dalian Liaoning 116013 China

When ship sails on the water surface, it will form a wake containing a large number of bubbles for different scales. The existence of bubbles will cause the attenuation of sound waves. In this paper, bubbles with different sizes are generated in the pool by using ceramic tube array. An experimental study on the acoustic attenuation characteristics of sound waves in bubbles was carried out for still water, small bubbles, medium-sized bubbles and large bubbles. Through experimental research, it is found that the existence of bubbles makes the acoustic signal decay obviously. At different frequencies, bubbles decay more than 10dB relative to still water. Large bubbles have the strongest attenuation effect on acoustic signals, averaging over 20dB. The medium and small bubbles are similar to the attenuation of the acoustic signal. The acoustic signal intensity in static water and different scale bubbles is basically the same as the frequency.

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How vehicle and fuel specifications affect evaporative and refuelling emissions from petrol vehicles

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Journal of Environmental Sciences 2025年

作者： Chunxiao Hao Yunshan Ge Xin Wang Jindong Liang Peng Chen Hong Bao Jiachen Li Dailin Yin Chongyao Wang Ruonan Li Junfang Wang Jia Ke Qing Liu Hang Yin National Laboratory of Automotive Performance & Emission Test School of Mechanical Engineering Beijing Institute of Technology Beijing 100081 China Key Laboratory for Vehicle Emission Control and Simulation of Ministry of Ecology and Environment Chinese Research Academy of Environmental Sciences Beijing 100012 China Beijing Smart Green Transport Research Centre Beijing 100022 China Pan Asia Technical Automotive Centre Co. Ltd. Shanghai 201206 China CATARC Automotive Test Centre Tianjin Co. Ltd. Tianjin 300300 China

Evaporative and refuelling emissions are a major source of volatile organic compound (VOC) contamination, contributing to ground-level ozone formation in China. To meet increasingly stringent evaporative emission control requirements, a growing number of newly certified vehicles have adopted onboard refuelling vapour recovery systems and updated canisters. This study aimed to evaluate the impact of vehicle and fuel specifications on evaporative and refuelling emissions from China-6 light-duty vehicles (LDVs). Two groups of experiments were conducted. In the first group, 28 tests were performed on China-6 LDVs and 24 on China-5 LDVs. The results showed that emissions from China-6 LDVs were significantly lower than those from China-5 LDVs in terms of total hydrocarbon emissions and diurnal losses over 0-24 h, with lower variability. In the second group, seven petrol fuel samples with varying aromatic formulations, ethanol contents, and vapour pressures were tested. Evaporative emissions and refuelling emissions were measured following China-6 procedures, while speciated VOCs were also quantified. The results showed that higher molecular weight aromatics more effectively suppressed evaporative emissions than toluene. Both E5 and E10 fuels increased vapour leakage during the diurnal-loss stage. Diurnal loss and refuelling emissions increased significantly with rising fuel Reid vapor pressure, particularly after the canister breakthrough on the second day. Speciated VOC analysis revealed that light alkanes dominated the escaped fuel vapour.

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Temperature Sensing Characteristics of Surface Acoustic Wave Brillouin Scattering in Optical Microfibers

Temperature Sensing Characteristics of Surface Acoustic Wave...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Yi Liu Yuanqi Gu Pengfei Chen Rongrong Guo Yao Yao Yajun You Wenjun He Xiu-Jian Chou Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology 79 West Yingze Street Taiyuan China Institute of Optoelectronic Engineering College of Physics and Optoelectronics Taiyuan University of Technology 79 West Yingze Street Taiyuan China Strong Digital Technology Co. Ltd. (Thinvent) Nanchang China Key Laboratory of Instrumentation Science and Dynamic Measurement Ministry of Education North University of China 3 Xueyuan Street Taiyuan China College of Mechatronics Engineering North University of China Taiyuan China Science and Technology on Electronic Test and Measurement Laboratory School of Instrument and Electronics North University of China Taiyuan China

ISBN: (纸本)9781665409889

Abstract-Temperature sensing characteristics of surface acoustic wave Brillouin scattering in 1-1.3 $\mu\mathrm{m}$ diameter optical microfibers are simulated by using the elastodynamic equation including the electrostrictive stress. A multi-peak Brillouin gain spectrum with rather high scattering efficiency is observed. The highest temperature sensitivity of the surface acoustic mode is 0.568 MHz/°C. Meanwhile, the temperature sensitivity of the surface acoustic mode is less affected by fiber diameter changes, ranging from 0.05 to 0.25 MHz/°C/$\mu\mathrm{m}$. It can be found that using SAW BS for temperature sensing would put less stress on manufacturing constraints for optical microfibers. Moreover, the results provide guidance for the further improving the performance of temperature sensing in the microelectronics field.

关键词： Temperature sensors Optical fibers Optical fiber sensors Temperature distribution Sensitivity Surface acoustic waves Microelectronics

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Two Laser Beam Modulation of Microstructure and Residual Stress Field in Cold Sprayed Al Alloy for Recovering Fatigue Performance

SSRN

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SSRN 2022年

作者： Pan, Xinlei Wang, Qiang Wen, Shifeng Li, Nan Yi, Min Zhu, Yiqi Shu, Song Nan, Jian Zhou, Liucheng Science and Technology on Plasma Dynamics Laboratory Air Force Engineering University Xi’an710038 China Institute of Aeronautics Engine School of Mechanical Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China School of Metallurgical Engineering Xi'an University of Architecture and Technology Xi’an710055 China Advanced Material Test Center School of Mechanics and Civil & Architecture Northwestern Polytechnical University Xi’an710055 China State Key Lab of Mechanics Control of Mechanical Structures College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing210016 China State Owned Machinery Factory Wuhu Wuhu241007 China

Cold spray process has been demonstrated to be an attractive additive manufacturing technology to develop freeform and coatings out of temperature-sensitive materials by high-velocity particle impact. However, because of lower bonding strength and inhomogeneous residual stress field distribution, the fatigue performance of cold sprayed deposition couldn’t satisfy the requirement in many engineering condition. In present work, we proposed a novel and promising approach to recover the fatigue performance of cold sprayed repairing components by two laser beams modulation, taken 7075 Al alloy as research object. In the treatment, one laser is used during CS process to irradiate the impact location via laser-induced thermal effects, by which the bonding mode is transformed from mechanical bonding to metallurgical bonding, thereby improving the bonding strength. And another laser is used as a post treatment to optimize the residual stress distribution by the mechanical effects of laser-induced ultrahigh shock wave below water confinement. Under such circumstances the fatigue performance of cold sprayed repairing Al samples is successfully brought back to a wrought/cast condition. Our work demonstrates that this combination of CS technology and laser process presents a wide range of possibilities for the further development of advanced additive manufacturing technology. © 2022, The Authors. All rights reserved.

关键词： Shock waves

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An Experimental Study on the Behavior Deterioration Trend of Friction Pendulum Bearings with Corrosion Time for Offshore Isolated Bridges 5

An Experimental Study on the Behavior Deterioration Trend of...

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2019 5th International Conference on Hydraulic and Civil Engineering, ICHCE 2019

作者： Zhao, Guifeng Ma, Yuhong Li, Yanmin Su, Liangjian Zhou, Fulin School of Civil Engineering Guangzhou University Guangzhou510006 China Earthquake Engineering Research and Test Center Key Laboratory of Seismic Control and Structural Safety Guangzhou University Guangzhou510405 China Guangdong Provincial Key Laboratory of Earthquake Engineering and Applied Technology Key Laboratory of Earthquake Resistance Earthquake Mitigation and Structural Safety Ministry of Education Guangzhou510405 China

At present, the behavior deterioration trend of friction pendulum bearings (FPBs) widely used in offshore bridges under marine environment isn't still clear. In this study, periodic-salt-spray and wetting-drying cycle accelerated corrosion tests were used to simulate the corrosion circumstances of FPBs in the splash and atmospheric zones, respectively. Eight sets of FPBs with a vertical bearing capacity of 35 t were designed as test samples. The environmental factors that affect the bearing behavior deterioration were analyzed;the test accelerated ratios of the factors were discussed;two kinds of test schemes were designed for the FPBs;and the macroscopic appearances of the FPBs at different corrosion times were observed. The trends of the initial static and dynamic friction coefficients with corrosion time were extensively analyzed, and the behavior deterioration trends of the mechanical properties of the FPBs were analyzed. The results show that in both the splash and atmospheric zones, the initial static and dynamic friction coefficients with corrosion time show an increasing periodic curve, but the behavior deterioration trend and period of FPBs in different locations are different. The vertical and horizontal stiffness of FPBs almost did not change with the corrosion time. The trends of equivalent damping ratio with the corrosion time are consistent with the dynamic friction coefficient. Based on the experimental results, the behavior deterioration trends of the initial static and dynamic friction coefficients of FPBs with corrosion time were obtained, which provides a basis for the seismic performance evaluations of offshore isolated bridges in their entire service lifetime. © Published under licence by IOP Publishing Ltd.

关键词： Deterioration

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Multi-Omics Approach Reveals Differences in Aroma and Metabolic Characteristics of Two Types of Jackfruits

SSRN

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SSRN 2025年

作者： Chen, Di Dong, Hailong Zhuang, Lvyun Wu, Xiaopeng Wu, Bing Lan, Weijie Su, Miaomiao Tao, Guanhua Xu, Bingqiang Xu, Chunhua Dong, Wenjiang Xu, Zhi Lyu, Daizhu Tan, Lehe Analysis and Test Center Chinese Academy of Tropical Agricultural Sciences Haikou571101 China College of Food Science and Technology Yunnan Agricultural University Kunming650000 China College of Plant Science and Technology Huazhong Agricultural University Wuhan43000 China Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable Ministry of Agriculture and Rural Affairs Haikou571101 China School of Chemical and Environmental Engineering Shanghai Institute of Technology Shanghai201418 China College of Food Science and Technology Nanjing Agricultural University Jiangsu Nanjing210095 China Hainan Provincial Key Laboratory of Quality and Safety for Tropical Fruit and Vegetable Products Haikou571101 China Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences Haikou571101 China Wanning571533 China

Consumers are particularly fond of jackfruit for its strong tropical aroma and distinctive flavor. However, significant differences in aroma and taste exist among various jackfruit varieties. This study investigated the aroma characteristics and metabolic profiles of two representative jackfruit cultivars, QY1H and XM1H. Results revealed distinct aroma profiles between the two varieties. Lipidomics analysis indicated remarkable differences in unsaturated fatty acid metabolism, with linoleic acid metabolism emerging as a key factor contributing to aroma variation. Differences in amino acid metabolism, particularly in leucine levels, were closely associated with aroma divergence in various jackfruit types. Additionally, carotenoid metabolism varied significantly between the two cultivars, with β-cyclocitral identified as a major aroma component in the XM1H variety. These findings provide new insights into the formation mechanisms of jackfruit aroma and offer valuable data for enhancing flavor quality and guiding future breeding programs. © 2025, The Authors. All rights reserved.

关键词： Linoleic acid

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Preselection based subjective preference evaluation for the quality of underwater images 32

Preselection based subjective preference evaluation for the ...

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32nd IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops, CVPRW 2019

作者： Yang, Miao Du, Yixiang Huang, Yue Liu, Hantao Wei, Zhiqiang Hu, Jintong Hu, Ke Sheng, Zhibin School of Electronic Engineering HuaiHai Institute of Technology China Marine Equipment and Technology Institute Jiangsu University of Science and Technology China Qingdao National Laboratory of Marine Science and Technology China Key Laboratory of Underwater Acoustic Communication and Marine Information Technology Ministry of Education China School of Computer Science and Informatics Cardiff University United Kingdom Ocean University of China School of Information Engineering Mining and Technology University of China School of Information and Control Engineering

ISBN: (纸本)9781728125060

underwater images contain an interactive mixture of distortions due to the physicochemical property of water and the instability of imaging systems, which differ from those in natural images. We cannot obtain the pristine underwater image as the reference applied in the traditional benchmark databases, and the groups of gradual distortions either. In this paper, a novel preselection based preference label evaluation method is proposed to construct a combined subjective test procedure for an extended preference judgment dataset of underwater images. To the best of our knowledge, this is the first subjective evaluation procedure for underwater images, and also a solution for an expanding visual preference benchmark database. We demonstrate the excellent correlation of the proposed subjective evaluation with the traditional image quality assessment. It is also proven that the proposed subjective evaluation procedure could reflect the slight change of image quality and the authentic quality of a picture more accurately better than the traditional methods. © 2019 IEEE Computer Society. All rights reserved.

关键词： Database systems

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Analysis of Influence Degree of Hydrological Parameters for Wave Induction Electric Field

Analysis of Influence Degree of Hydrological Parameters for ...

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IEEE Information technology and Mechatronics Engineering Conference (ITOEC)

作者： Pei Cui Jun Shao Shaojie Pang Science and Technology on Underwater Test and Control Laboratory Dalian Scientific Test and Control Technology Institute Dalian China

ISBN: (纸本)9781538653746

The underwater electromagnetic field of marine environment is the background for the underwater vehicle to complete underwater electromagnetic communication. The characteristics of the electromagnetic field of marine environment directly affect the quality of underwater electromagnetic communication. And as the main source of the electromagnetic field of marine environment, the wave induced electromagnetic field is an important research object for domestic and foreign relevant personnel. Because of its complicated production mechanism, many hydrological parameters affect its amplitude distribution. The hydrological impact parameters of it are combed based on the analysis results of wave induced electric field theory in this paper. Combined with the actual hydrological parameter values, we determined the degree of influence of each hydrological parameter in the wave induced electric field and gave the key parameters affecting its amplitude. The research results of this paper can provide references for the establishment of wave induced electric field observation methods and statistical models. Based on the research results of this paper, the amplitude and spatial variation of underwater electric field in different depths under different hydrological parameters can be determined. The conclusions can provide reference information for electromagnetic communication frequency and depth selection of underwater vehicle.

关键词： Electric fields Magnetic fields Surface waves Sea surface

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