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Data-Driven Fault Detection of multiple Open-Circuit Faults for mmC Systems Based on Long Short-Term memory Networks

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1563-1574页

作者： Chenxi Fan Kaishun Xiahou Lei wang q.H.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

This paper presents a long short-term memory(LSTm)-based fault detection method to detect the multiple open-circuit switch faults of modular multilevel converter(mmC)systems with full-bridge sub-modules(FB-Sms).Eighteen sensor signals of grid voltages,grid currents and capacitance voltages of mmC for single and multi-switch faults are collected as sampling *** output signal characteristics of four types of single switch faults of FB-Sm,as well as double switch faults in the same and different phases of mmC,are analyzed under the conditions of load variations and control command changes.A multi-layer LSTm network is devised to deeply extract the fault characteristics of mmC under different faults and operation conditions,and a Softmax layer detects the fault *** results have confirmed that the proposed LSTm-based method has better detection performance compared with three other methods:K-nearest neighbor(KNN),naive bayes(NB)and recurrent neural network(RNN).In addition,it is highly robust to model uncertainties and Gaussian *** validity of the proposed method is further demonstrated by experiment studies conducted on a hardware-in-the-loop(HIL)testing platform.

关键词： Fault detection long short-term memory(LSTm) modular multilevel converter(mmC) open circuit fault

Probing the Bardeen-Kiselev black hole with the cosmological constant caused by Einstein equations coupled with nonlinear electrodynamics using quasinormal modes and greybody bounds

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Communications in Theoretical Physics 2024年第6期76卷 102-119页

作者： S R Wu B q wang Z W Long College of Physics Guizhou UniversityGuiyang 550025China College Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China

In this work,we investigate a static and spherically symmetric Bardeen-Kiselev black hole(BH)with the cosmological constant,which is a solution of the Einstein-non-linear maxwell field *** compute the quasinormal frequencies for the Bardeen-Kiselev BH with the cosmological constant due to electromagnetic and gravitational *** varying the BH parameters,we discuss the behavior of both real and imaginary parts of the BH quasinormal frequencies and compare these frequencies with the Reissner-Nordström-de Sitter BH surrounded by quintessence(RN-dSq).Interestingly,it is shown that the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSq under electromagnetic perturbations are different when the charge parameter q,the state parameter w and the normalization factor c are varied;however,for the gravitational perturbations,the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSq are different only when the charge parameter q is ***,compared with the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime *** interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the Bardeen-Kiselev BH with the cosmological constant damps faster and oscillates slowly;for the gravitational perturbations,the quasinormal mode decays slowly and oscillates *** also study the reflection and transmission coefficients along with the absorption cross section in the Bardeen-Kiselev BH with the cosmological constant;it is shown that the transmission coefficients will increase due to the presence of Kiselev quintessence.

关键词： quasinormal modes greybody factors Bardeen-Kiselev black hole with cosmological constant

Precipitation of multi-type nano-quasicrystals in a mg-Zn-Y alloy

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Journal of magnesium and Alloys 2024年第3期12卷 997-1008页

作者： W.Z.wang X.Z.Zhou L.F.Zhang H.q.Ye Z.q.Yang Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of ScienceShenyang 110016China Ji Hua Laboratory Foshan 528251China Foshan University Foshan 528231China

mg-6Zn-1Y(at.%)ribbons with strengthening precipitates of multi-type nanoquasicrystals were prepared by melt-spinning followed by aging *** evolution of the rapidly solidified ribbons during isothermal aging was comprehensively studied using various electron microscopy *** new kinds of decagonal quasicrystals were formed in aged ribbons,in addition to precipitation of nanometer icosahedral ***-resolution observations reveal that both decagonal quasicrystals can be modeled by quasiperiodic tiling with decagonal clusters of 2.5 nm in diameter,but overlap of neighboring clusters in both decagonal quasicrystals is different from the Gummelt model observed in other quasicrystals.A shell composed of complex Laves mg-Zn domains was formed surrounding each decagonal quasicrystal precipitate upon prolonged *** addition,all kinds of nanoprecipitates exhibit excellent structure and size stability at 573 *** findings may have implications for not only fundamental studies about quasicrystals,but also microstructural manipulation of high-performance mg alloys.

关键词： quasicrystal mg alloys Rapid solidification Scanning-transmission electron microscopy.

Simulation Analysis of Deformation Control for magnetic Soft medical Robots

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 794-796页

作者： Jingxi wang Baoyu Liu Edmond q.Wu Jin ma Ping Li Key Laboratory of Biomechanics and mechanobiology(Beihang University) Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineeringthe School of Biological Science and Medical EngineeringBeihang UniversityBeijing100083China IEEE the Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China the Department of Aerospace medicine Air Force Medical UniversityXi’an 710032China

Dear Editor,This letter presents a biocompatible cross-shaped magnetic soft robot and investigates its deformation mode control strategy through COmSOL modeling and *** soft robots offer novel avenues for precise trea... 详细信息

关键词： robot simulation COmSOL

Skin supersoliditymatters the performance and functionality of water droplets

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Droplet 2024年第4期3卷 1-9页

作者： Chang q.Sun Yong Zhou Hengxin Fang Biao wang RISE and School of materials Science&Engineering Dongguan University of TechnologyDongguanChina School of Physics&Sino-French Institute of Nuclear Engineering&Technology Sun Yat-Sen UniversityGuangzhouChina Guangdong Provincial Key Laboratory of Extreme Conditions DongguanChina

Even more fascinating than its bulk parent,a water droplet possesses extraordinary catalytic and hydro-voltaic capability,elastic adaptivity,hydrophobicity,sensitivity,thermal stability,etc.,but the underlying mechanism is still *** emphasize herewith that the H‒O bond follows the universal bond order‒length‒strength cor-relation and nonbonding electron polarization regulation and the hydrogen bond cooperativity and polarizability notion regulates the performance of the coupling hydrogen bond(O:H‒O).Computational and spectrometric evidence consistently shows that molecular undercoordination shortens the intramolecular H‒O bond by up to 10%while lengthening the intermolecular O:H nonbond by 20%cooperatively with an association of electron polarization,making the 0.3-nm thick droplet skin of a supersolid phase of *** supersolid skin dictates the performance and functionality of the droplet in chemical,dielectric,electrical,mechanical,optical,and thermal properties as well as the transport dynamics of electrons and *** amplification of these findings could deepen our insight into the undercoordi-nated aqueous systems,including bubbles and molecular clusters,and promote deep engineering of water and ice.

关键词： performance solid bonding

In situ digital testing method for quality assessment of soft soil improvement with polyurethane

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Journal of Rock mechanics and Geotechnical Engineering 2024年第5期16卷 1732-1748页

作者： X.F.wang C.J.wang W.V.Yue Z.J.Zhang Z.q.Yue Department of Civil Engineering China University of Geosciences (Beijing)BeijingChina Department of Water Science and Engineering Zhengzhou UniversityZhengzhouChina Department of Geotechnical Engineering Tongji UniversityShanghaiChina Department of Civil Engineering The University of Hong KongChina

This study purposes an in situ testing method on quality assessment of soil *** drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring *** factual drilling data can characterize the degree of soil improvement by penetration injection with permeable *** from on-site drilling monitoring shows that the linear zones represent constant drilling speeds shown in the plot of drill bit advancement *** drilling time,which indicates the spatial distributions of soil *** soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky *** results of soil profile are verified by the parallel site *** constant drilling speeds profile the coring-resistant strength of drilled *** comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty *** tests,*** compressive strength(UCS)test,have been performed with core sample to investigate and characterize in situ strength by comparing that with drilling *** show that the average predicted strengths of treated silty clay are 2.4-6.9 times higher than the average measured strength of untreated silty *** UCS-based indices of 374.5%and 344.2%verified the quality assessment(qA)results by this new in situ *** method provides a cost-effective tool for quality assessment of soil improvement by utilizing the digital drilling data.

关键词： Drilling process monitoring system Hydraulic rotary drilling process Constant drilling speed Soil improvement quality assessment

A Preliminary Comparative Study on the Centering Algorithms for CassiniISS NAC Images

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Research in Astronomy and Astrophysics 2024年第10期24卷 58-65页

作者： T.Liang q.-F.Zhang G.-m.Liu W.-H.Zhu C.-S.wang Department of Computer Science Jinan UniversityGuangzhou 510632China Sino-French Joint Laboratory for Astrometry Dynamics and Space ScienceJinan UniversityGuangzhou 510632China School of Computer Science Guangdong University of EducationGuangzhou 510303China

Obtaining high precision is an important consideration for astrometric studies using images from the Narrow Angle Camera(NAC)of the Cassini Imaging Science Subsystem(ISS).Selecting the best centering algorithm is key to enhancing astrometric *** this study,we compared the accuracy of five centering algorithms:Gaussian fitting,the modified moments method,and three point-spread function(PSF)fitting methods(effective PSF(ePSF),PSFEx,and extended PSF(x PSF)from the Cassini Imaging Central Laboratory for Operations(CICLOPS)).We assessed these algorithms using 70 ISS NAC star field images taken with CL1 and CL2 filters across different stellar *** ePSF method consistently demonstrated the highest accuracy,achieving precision below 0.03 pixels for stars of magnitude *** to the previously considered best,the modified moments method,the e PSF method improved overall accuracy by about 10%and 21%in the sample and line directions,***,the xPSF model provided by CICLOPS had lower precision than the ***,the ePSF exhibits an improvement in measurement precision of 23%and 17%in the sample and line directions,respectively,over the *** discrepancy might be attributed to the xPSF focusing on photometry rather than *** findings highlight the necessity of constructing PSF models specifically tailored for astrometric purposes in NAC images and provide guidance for enhancing astrometric measurements using these ISS NAC images.

关键词： methods:analytical techniques:image processing stars:imaging astrometry

mechanical Behavior of Bamboo,and Its Biomimetic Composites and Structural members:A Systematic Review

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Journal of Bionic Engineering 2024年第1期21卷 56-73页

作者： Shanyu Han Yuyuan He Hanzhou Ye Xueyong Ren Fuming Chen Kewei Liu Sheldon q.Shi Ge wang Institute of Biomaterials for Bamboo and Rattan Resources International Centre for Bamboo and RattanBeijing 100102China Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo&Rattan Science and Technology Beijing 100102China National Forestry and Grassland Engineering Technology Center for Wood Resources Recycling College of Materials Science and TechnologyBeijing Forestry UniversityBeijing 100083China International Bamboo and Rattan Organization Beijing 100102China School of Civil Engineering Tsinghua UniversityBeijing 100084China mechanical Engineering Department University of North TexasDentonTX 762077102USA

Bamboo is a typical biological material widely growing in nature with excellent physical and mechanical *** is lightweight with high strength and *** naturally optimized bamboo structure,which has inspired global material scientists and engineers for decades,is significantly important for the bionic design of novel structural materials with ultra-light,ultra-strong,or ultra-tough and comprehensive *** literature on innovative composite materials and structural members inspired by bamboo are reviewed in this paper,and the research progress and prospects in this field are expounded in three ***,the structural characteristics of the bamboo wall layer along the thickness and height directions are described in terms of chemical composition,gradient structure,pore structure,and hollow structure with variable ***,this paper summarizes the research progress on new composite materials and structural components by applying bamboo’s structural features from the perspective of sustainability,designability,and ***,given the limitations of current research,the biomimetic scientific research on bamboo’s structural characteristics is prospected from the interpretation of bamboo structure,new bamboo-like materials,and structural design optimization perspectives,providing a reference for future research on biomimetic aspects of biomass.

关键词： Bamboo Structural characteristics-Bamboo-like material Physical and mechanical properties

Rescattering of stimulated Raman side scattering in nonuniform plasmas

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matter and Radiation at Extremes 2024年第5期9卷 68-76页

作者： S.Tan q.wang Y.Chen W.B.Yao C.Z.Xiao J.F.myatt School of Physics and Electronics Hunan UniversityChangsha 410082China Institute of Applied Physics and Computational mathematics Beijing 100094China School of Electrical and Information Engineering Anhui University of Science and TechnologyHuainanAnhui 232001China Department of Electrical and Computer Engineering University of Alberta9211116 St.NWEdmontonAlberta T6G 1H9Canada

Rescattering of stimulated Raman side scattering(SRSS)is observed for the first time via two-dimensional(2D)particle-in-cell(PIC)*** construct a theoretical model for the rescattering process,which can predict the region of occurrence of mth-order SRSS and estimate its *** rescattering process is identified by the 2D PIC simulations under typical conditions of a direct-drive inertial confinement fusion *** electrons produced by second-order SRSS propagate nearly perpendicular to the density gradient and gain nearly the same energy as in first-order SRSS,but there is no cascade acceleration to produce superhot *** studies for a wide range of ignition conditions show that SRSS and associated rescatterings are robust and important processes in inertial confinement fusion.

关键词： nonuniform acceleration scattering