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Research on multi-parametric sensors based on multi-mode microfiber

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Optoelectronics Letters 2024年第1期20卷 18-22页

作者： DONG Taiji LIU Xu WANG Yunkai GAO Bingkun JIANG Chunlei WANG Xiufang college of electrical and Information engineering Northeast Petroleum UniversityDaqing 163318China

A multi-parametric sensor based on multi-mode microfiber(MMF)is proposed,utilizing the modal interference between HE11mode and HE12mode in the elongated multi-mode fiber to achieve the temperature and pressure *** this paper,the simulation model of modal interference based on MMF is established and the mechanism of modal interference is *** the different mechanisms of modal response in the fiber at different wavelengths,the temperature was inverted using the offset of wavelengths in the spectrum,and the pressure was measured using the change of light *** independent measurement of temperature and pressure was *** experimental results show that the sensor has a temperature sensitivity of 1.305 nm/℃.In the case of pressure sensing,the sensor shows a sensitivity of-0.163 d Bm/g.

关键词： measurement mode modal

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Improved Convolutional Neural Network for Traffic Scene Segmentation

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Computer Modeling in engineering & Sciences 2024年第3期138卷 2691-2708页

作者： Fuliang Xu Yong Luo Chuanlong Sun Hong Zhao college of Mechanical and electrical engineering Qingdao UniversityQingdao266071China

In actual traffic scenarios,precise recognition of traffic participants,such as vehicles and pedestrians,is crucial for intelligent *** study proposes an improved algorithm built on Mask-RCNN to enhance the ability of autonomous driving systems to recognize traffic *** algorithmincorporates long and shortterm memory networks and the fused attention module(GSAM,GCT,and Spatial Attention Module)to enhance the algorithm’s capability to process both global and local ***,to increase the network’s initial operation stability,the original network activation function was replaced with Gaussian error linear *** were conducted using the publicly available Cityscapes *** the test results,it was observed that the revised algorithmoutperformed the original algorithmin terms of AP_(50),AP_(75),and othermetrics by 8.7%and 9.6%for target detection and 12.5%and 13.3%for segmentation.

关键词： Instance segmentation deep learning convolutional neural network attention mechanism

Squeeze and Excitation Convolution with Shortcut for Complex Plasma Image Recognition

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Computers, Materials & Continua 2024年第8期80卷 2221-2236页

作者： Baoxia Li Wenzhuo Chen Xiaojiang Tang Shaohuang Bian Yang Liu Junwei Guo Dan Zhang Feng Huang college of Information and electrical engineering China Agricultural UniversityBeijing100083China college of Science China Agricultural UniversityBeijing100083China

Complex plasma widely exists in thin film deposition,material surface modification,and waste gas treatment in industrial plasma *** complex plasma discharge,the configuration,distribution,and size of particles,as well as the discharge glow,strongly depend on discharge ***,traditional manual diagnosis methods for recognizing discharge parameters from discharge images are complicated to operate with low accuracy,time-consuming and high requirement of *** solve these problems,by combining the two mechanisms of attention mechanism(strengthening the extraction of the channel feature)and shortcut connection(enabling the input information to be directly transmitted to deep networks and avoiding the disappearance or explosion of gradients),the network of squeeze and excitation convolution with shortcut(SECS)for complex plasma image recognition is proposed to effectively improve the model *** results show that the accuracy,precision,recall and F1-Score of our model are superior to other models in complex plasma image recognition,and the recognition accuracy reaches 97.38%.Moreover,the recognition accuracy for the Flowers and Chest X-ray publicly available data sets reaches 97.85%and 98.65%,respectively,and our model has *** study shows that the proposed model provides a new method for the diagnosis of complex plasma images and also provides technical support for the application of plasma in industrial production.

关键词： Image recognition complex plasmas deep learning

Hierarchical Control Strategy for Load Regulation Based on Stackelberg Game Theory Considering Randomness

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 929-941页

作者： Tingyu Jiang Ping Ju C.Y.Chung Yuzhong Gong college of Energy and electrical engineering Hohai UniversityNanjing 211100China Department of electrical engineering City University of Hong KongHong Kong CF624China Department of electrical and Computer engineering University of SaskatchewanSaskatoonSK S7N 5A9Canada CSEE IEEE

Demand response has been recognized as a valuable functionality of power systems for mitigating power *** paper proposes a hierarchical control strategy among the distribution system operator(DSO),load aggregators(LAs),and thermostatically controlled loads(TCLs);the strategy includes a scheduling layer and an executive layer to provide load *** the scheduling layer,the DSO(leader)offers compensation price(CP)strategies,and the LAs(followers)respond to CP strategies with available regulation power(ARP)*** of the DSO and LAs are modeled according to their behaviors during the load regulation *** game is adopted to capture interactions among the players and leader and to obtain the optimal strategy for each participant to achieve ***,considering inevitable random factors in practice,e.g.,renewable generation and behavior of users,two different stochastic models based on sample average approximation(SAA)and parameter modification are formulated with improved scheduling *** the executive layer,distributed TCLs are triggered based on strategies determined in the scheduling layer.A self-triggering method that does not violate user privacy is presented,where TCLs receive external signals from the LA and independently determine whether to alter their operation *** simulations are performed on the modified IEEE-24 bus system to verify effectiveness of the proposed strategy.

关键词： Demand response hierarchical control load regulation self-triggering method Stackelberg game

Transient Voltage Support Strategy of Grid-forming Medium Voltage Photovoltaic Converter in the LCC-HVDC System

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 1849-1864页

作者： Hong Lu Xianyong Xiao Guangfu Tang Zhiyuan He Zhiguang Lin Chong Gao Zixuan Zheng college of electrical engineering Sichuan UniversityChengdu 610065China State Key Lab of Advance Power Transmission Technology China Electric Power Research InstituteBeijing 100192China college of electrical engineering Sichuan UniversityChengdu 610065China.

The participation of photovoltaic(PV)plants in supporting the transient voltage caused by commutation failure in the line-commutated-converter-based high voltage direct current(LCC-HVDC)system is of great significance,as it can enhance the DC transmission ***,it is found that the gridfollowing(GFL)PV converters face the problem of mismatch between reactive power response and transient voltage characteristic when the voltage converts from low voltage to overvoltage,further aggravating the overvoltage ***,this article proposes a transient voltage support strategy based on the gridforming(GFM)medium voltage PV *** proposed strategy takes the advantage of the close equivalent electrical distance between the converter and grid,which can autonomously control the converter terminal voltage through GFM control with adaptive voltage droop *** simulation results show that the proposed strategy can ensure the output reactive power of the PV converter quickly matches the transient voltage characteristic at different stages,indicating that the proposed strategy can effectively support the transient voltage.

关键词： Commutation failure grid-forming(GFM) photovoltaic(PV)converter reactive power response transient voltage

Parametric Optimization of Wheel Spoke Structure for Drag Reduction of an Ahmed Body

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Computer Modeling in engineering & Sciences 2024年第4期139卷 955-975页

作者： Huihui Zhai Dongqi Jiao Haichao Zhou Institute of electrical and Information engineering Zhenjiang CollegeZhenjiang212028China School of Automotive and Traffic engineering Jiangsu UniversityZhenjiang212013China

The wheels have a considerable influence on the aerodynamic properties and can contribute up to 25%of the total drag on modern *** this study,the effect of the wheel spoke structure on the aerodynamic performance of the isolated wheel is ***,the 35°Ahmed body with an optimized spoke structure is used to analyze the flow behavior and the mechanism of drag *** Fluent software is employed for this investigation,with an inlet velocity of 40 m/*** accuracy of the numerical study is validated by comparing it with experimental results obtained from the classical Ahmed *** gain a clearer understanding of the effects of the wheel spoke parameters on the aerodynamics of both the wheel and Ahmedmodel,and five design variables are proposed:the fillet angleα,the inside arc radius R1,the outside radius R2,and the same length of the chord L1 and *** variables characterize the wheel spoke *** Optimal Latin Hypercube designmethod is utilized to conduct the experimental *** on the simulation results of various wheel spoke designs,the Kriging model and the adaptive simulated annealing algorithm is selected to optimize the design *** objective is to achieve the best combination for maximum drag *** is indicated that the optimized spoke structure resulted in amaximum drag reduction of 5.7%and 4.7%for the drag coefficient of the isolated wheel and Ahmed body,*** drag reduction is primarily attributed to changes in the flow state around the wheel,which suppressed separation ***,it influenced the boundary layer thickness around the car body and reduced the turbulent kinetic energy in the wake *** effects collectively contributed to the observed drag reduction.

关键词： Ahmed body wheel spoke design parameter optimization drag reduction numerical simulation

Numerical Simulation and Optimization of the Gas-Solid Coupled Flow Field and Discharging Performance of Straw Crushers

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Fluid Dynamics and Materials Processing 2024年第11期20卷 2565-2583页

作者： Yuezheng Lan Yu Zhao Zhiping Zhai Meihua Fan Fushun Li college of Mechanical engineering Inner Mongolia University of TechnologyHohhot010051China college of Mechanical&electrical engineering Qiqihar UniversityQiqihar161000China

The quality of crushing, power consumption, and discharging performance of a straw crusher are greatly influenced by the characteristics of its internal flow field. To enhance the straw crusher’s flow field properties and improve the efficiency with which crushed material is discharged, first, the main structural parameters influencing the air flow in the crusher are discussed. Then, the coupled gas-solid flow field in the straw crusher is numerically calculated through solution of the Navier-Stokes equations and application of the discrete element method (DEM). Finally, the discharge performance index of the crusher is examined through detailed analysis of the crushed material dynamics. Additionally, a multi-island genetic algorithm is used to optimize the structure and operational factors that have significant effects on the discharge performance. With optimization, the accumulation rate of crushed materials in the bottom region of the straw crusher decreases by 20.08%, and the mass flow rate at the discharge outlet increases by 11.63%.

关键词： Straw crusher CFD–DEM gas-solid coupling flow field discharging performance multi-island genetic algorithm

Effect of dielectric material on the uniformity of nanosecond pulsed dielectric barrier discharge

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Plasma Science and Technology 2024年第9期26卷 79-87页

作者： Wenhao ZHOU Dongxuan ZHANG Xiaohui DUAN Xi ZHU Feng LIU Zhi FANG college of electrical engineering and Control Science Nanjing Tech UniversityNanjing 211816People’s Republic of China

Dielectric barrier discharge(DBD)is considered as a promising technique to produce large volume uniform plasma at atmospheric pressure,and the dielectric barrier layer between the electrodes plays a key role in the DBD processes and enhancing discharge *** this work,the uniformity and discharge characteristics of the nanosecond(ns)pulsed DBD with dielectric barrier layers made of alumina,quartz glass,polycarbonate(PC),and polypropylene(PP)are investigated via discharge image observation,voltage-current waveform measurement and optical emission spectral *** analyzing discharge image by gray value standard deviation method,the discharge uniformity is quantitatively *** effects of the space electric field intensity,the electron density(Ne),and the space reactive species on the uniformity are studied with quantifying the gap voltage Ug and the discharge current Ig,analyzing the recorded optical emission spectra,and simulating the temporal distribution of Ne with a one-dimensional fluid *** is found that as the relative permittivity of the dielectric materials increases,the space electric field intensity is enhanced,which results in a higher Ne and electron temperature(Te).Therefore,an appropriate value of space electric field intensity can promote electron avalanches,resulting in uniform and stable plasma by the merging of electron ***,an excessive value of space electric field intensity leads to the aggregation of space charges and the distortion of the space electric field,which reduce the discharge *** surface roughness and the surface charge decay are measured to explain the influences of the surface properties and the second electron emission on the discharge *** results in this work give a comprehensive understanding of the effect of the dielectric materials on the DBD uniformity,and contribute to the selection of dielectric materials for DBD reactor and the realization of atmospheric pre

关键词： dielectric barrier discharge dielectric material uniformity discharge characteristics

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An evolutionary multiobjective method based on dominance and decomposition for feature selection in classification

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Science China(Information Sciences) 2024年第2期67卷 5-19页

作者： Jing LIANG Yuyang ZHANG Ke CHEN Boyang QU Kunjie YU Caitong YUE Ponnuthurai Nagaratnam SUGANTHAN School of electrical and Information engineering Zhengzhou University State Key Laboratory of Intelligent Agricultural Power Equipment School of electrical engineering and Automation Henan Institute of Technology School of Electronics and Information Zhongyuan University of Technology KINDI Center for Computing Research College of EngineeringQatar University

Feature selection in classification can be considered a multiobjective problem with the objectives of increasing classification accuracy and decreasing the size of the selected feature subset. Dominance-based and decomposition-based multiobjective evolutionary algorithms(MOEAs) have been extensively used to address the feature selection problem due to their strong global search capability. However, most of them face the problem of not effectively balancing convergence and diversity during the evolutionary process. In addressing the aforementioned issue, this study proposes a unified evolutionary framework that combines two search forms of dominance and decomposition. The advantages of the two search methods assist one another in escaping the local optimum and inclining toward a balance of convergence and diversity. Specifically, an improved environmental selection strategy based on the distributions of individuals in the objective space is presented to avoid duplicate feature subsets. Furthermore, a novel knowledge transfer mechanism that considers evolutionary characteristics is developed, allowing for the effective implementation of positive knowledge transfer between dominance-based and decomposition-based feature selection methods. The experimental results demonstrate that the proposed algorithm can evolve feature subsets with good convergence and diversity in a shorter time compared with 9 state-of-the-art feature selection methods on 20 classification problems.

关键词： evolutionary algorithms feature selection multiobjective optimization knowledge transfer classification