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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 189-201页

作者： Zhao Shi yan Xu Dunjian Xie Shiwei Xie Amer M.y.M.Ghias Nanyang Technological University Singapore the School of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108China

This paper proposes a new method for service restoration of distribution network with the support of transportable power sources(TPSs)and repair crews(RCs).Firstly,a coupling model of distribution networks and vehicle routing of TPSs and RCs is proposed,where the TPSs serve as emergency power supply sources,and the RCs are used to repair the faulted *** the uncertainty of traffic congestion,the probability distribution of the travel time spent on each road is derived based on the Nesterov user equilibrium model,and a two-stage stochastic program is formulated to determine the optimal routings of TPSs and *** efficiently solve the proposed stochastic mixed-integer linear program(MILP),a two-phase scenario reduction method is then developed to scale down the problem size,and an adaptive progressive hedging algorithm is used for an efficient *** effectiveness of the proposed methods and algorithms has been illustrated in a modified IEEE 33-bus system.

关键词： Service restoration distribution network traffic uncertainty transportable power source repair crew stochastic program

HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9

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Research in Astronomy and Astrophysics 2024年第1期24卷 292-299页

作者： yan Guo C.Sengupta T.C.Scott P.Lagos y.Luo Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China Institute of Astrophysics and Space Sciences(IA Porto) Rua das Estrelas4150-762PortoPortugal

We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a Tidal Dwarf Galaxy(TDG) candidate. TDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. The quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved TDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the *** detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment.

关键词： galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM

Thermosphere joint observations by TM-1 constellations and Swarm-B during the April 2023 geomagnetic storm

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Earth and Planetary Physics 2024年第2期8卷 307-316页

作者： yongPing Li yueQiang Sun XianGuo Zhang JiangZhao ai XiaoLiang Zheng Jia Li yuJie Wang BiBo Guo Feng yan ShiLong Wei XinChun Tang yuanyuan Cao National Space Science Center Chinese Academy of SciencesBeijing 100190China Beijing Key Laboratory of Space Environment Exploration Beijing 100190China Key Laboratory of Science and Technology on Space Environment Situational Awareness Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Shenzhen Aerospace Dongfanghong Satellite LtdShenzhen 518057China

The response of thermosphere density to geomagnetic storms is a complicated physical ***-satellite joint observations at the same altitude but different local times(LTs)are important for understanding this process;however,until now such studies have hardly been *** this report,we analyze in detail the thermosphere mass density response at 510 km during the April 23−24,2023 geomagnetic storm using data derived from the TM-1(TianMu-1)satellite constellation and Swarm-B *** observations show that there were significant LT differences in the hemispheric asymmetry of the thermosphere mass density during the geomagnetic *** observed by satellite TM02 at nearly 11.3 and 23.3 LTs were larger in the northern hemisphere than in the *** TM04 dayside density observations appear to be almost symmetrical with respect to the equator,though southern hemisphere densities on the nightside were ***-B data exhibit near-symmetry between the *** addition,the mass density ratio results show that TM04 nightside observations,TM02 data,and Swarm-B data all clearly show stronger effects in the southern hemisphere,except for TM04 on the dayside,which suggest hemispheric *** South-North density enhancement differences in TM02 and TM04 on dayside can reach 130%,and Swarm-B data even achieve 180%*** the observations of all three satellites,large-scale traveling atmospheric disturbances(TADs)first appear at high latitudes and propagate to low latitudes,thereby disturbing the atmosphere above the equator and even into the opposite ***00 model simulations were also performed on this geomagnetic *** are absent in the NRLMSISE00 *** satellite data suggest that NRLMSISE00 significantly underestimates the magnitude of the density response of the thermosphere during geomagnetic storms,especially at high latitudes in both ***,use of the density simulation of NRLM

关键词： TM-1 constellation Swarm-B joint observations geomagnetic storm Local Times

Physics-informed deep learning for fringe pattern analysis

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Opto-Electronic Advances 2024年第1期7卷 4-15页

作者： Wei yin yuxuan Che Xinsheng Li Mingyu Li yan Hu Shijie Feng Edmund y.Lam Qian Chen Chao Zuo Smart Computational Imaging Laboratory(SCILab) School of Electronic and Optical EngineeringNanjing University of Science and TechnologyNanjing 210094China Smart Computational Imaging Research Institute(SCIRI)of Nanjing University of Science and Technology Nanjing 210019China Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense Nanjing 210094China Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong Kong SAR 999077China

Recently,deep learning has yielded transformative success across optics and photonics,especially in optical *** neural networks (DNNs) with a fully convolutional architecture (e.g.,U-Net and its derivatives) have been widely implemented in an end-to-end manner to accomplish various optical metrology tasks,such as fringe denoising,phase unwrapping,and fringe ***,the task of training a DNN to accurately identify an image-to-image transform from massive input and output data pairs seems at best naive,as the physical laws governing the image formation or other domain expertise pertaining to the measurement have not yet been fully exploited in current deep learning *** this end,we introduce a physics-informed deep learning method for fringe pattern analysis (PI-FPA) to overcome this limit by integrating a lightweight DNN with a learning-enhanced Fourier transform profilometry (Le FTP) *** parameterizing conventional phase retrieval methods,the Le FTP module embeds the prior knowledge in the network structure and the loss function to directly provide reliable phase results for new types of samples,while circumventing the requirement of collecting a large amount of high-quality data in supervised learning *** by the initial phase from Le FTP,the phase recovery ability of the lightweight DNN is enhanced to further improve the phase accuracy at a low computational cost compared with existing end-to-end *** results demonstrate that PI-FPA enables more accurate and computationally efficient single-shot phase retrieval,exhibiting its excellent generalization to various unseen objects during *** proposed PI-FPA presents that challenging issues in optical metrology can be potentially overcome through the synergy of physics-priors-based traditional tools and data-driven learning approaches,opening new avenues to achieve fast and accurate single-shot 3D imaging.

关键词： optical metrology deep learning physics-informed neural networks fringe analysis phase retrieval

Game Theory based Optimal Defensive Resources Allocation with Incomplete Information in Cyber-physical Power Systems against False Data Injection Attacks

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Protection and Control of Modern Power Systems 2024年第2期9卷 115-127页

作者： Bingjing yan Zhenze Jiang Pengchao yao Qiang yang Wei Li Albert y.Zomaya College of Electrical Engineering Zhejiang University College of Control Science and Engineering Zhejiang University College of Electrical Engineering Zhejiang UniversityHangzhou 310027China School of Information Technologies at The University of Sydney School of Information Technologies

Modern power grid is fast emerging as a complex cyber-physical power system(CPPS)integrating physical current-carrying components and processes with cyber-embedded computing,which faces increasing cy-berspace security threats and *** this paper,the state(i.e.,voltage)offsets resulting from false data injection(FDI)attacks and the bus safety characterization are applied to quantify the attack *** state offsets are obtained by the state estimation method,and the bus safety characterization considers the power net-work topology as well as the vulnerability and connection relationship of *** the indeterminacy of attacker’s resource consumption and reward,a zero-sum game-theoretical model from the defender’s perspective with incomplete information is explored for the optimal allocation of limited defensive *** attacker aims to falsify measurements without triggering threshold alarms to break through the protection,leading to load shedding,over-voltage or *** defender attempts to ensure the estimation results to be as close to the actual states as possible,and guarantee the system’s safety and efficient defensive resource *** proposed solution is extensively evaluated through simu-lations using the IEEE 33-bus test network and real-time digital simulator(RTDS)based testbed experiments of the IEEE 14-bus *** results demonstrate the effec-tiveness of the proposed game-theoretical approach for optimal defensive resource allocation in CPPS when lim-ited resources are available when under FDI *** Terms—Optimal strategy,game theory,Nash equilibrium,CPPS,FDI attack.

关键词： Optimal strategy game theory Nash equilibrium CPPS FDI attack

SEMI-IMPLICIT SPECTRAL DEFERRED CORRECTION METHODS BASED ON SECOND-ORDER TIME INTEGRATION SCHEMES FOR NONLINEAR PDES

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Journal of Computational Mathematics 2024年第1期42卷 111-133页

作者： Ruihan Guo yan Xu School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China

In[20],a semi-implicit spectral deferred correction(SDC)method was proposed,which is efficient for highly nonlinear partial differential equations(PDEs).The semi-implicit SDC method in[20]is based on first-order time integration methods,which are corrected iteratively,with the order of accuracy increased by one for each additional *** this paper,we will develop a class of semi-implicit SDC methods,which are based on second-order time integration methods and the order of accuracy are increased by two for each additional *** spatial discretization,we employ the local discontinuous Galerkin(LDG)method to arrive at fully-discrete schemes,which are high-order accurate in both space and *** experiments are presented to demonstrate the accuracy,efficiency and robustness of the proposed semi-implicit SDC methods for solving complex nonlinear PDEs.

关键词： Spectral deferred correction method Nonlinear PDEs Local discontinuous Galerkin method Second-order scheme

Recent innovations in laser additive manufacturing of titanium alloys

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International Journal of Extreme Manufacturing 2024年第3期6卷 2-37页

作者： Jinlong Su Fulin Jiang Jie Teng Lequn Chen Ming yan Guillermo Requena Lai-Chang Zhang y Morris Wang Ilya V Okulov Hongmei Zhu Chaolin Tan College of Materials Science and Engineering Hunan UniversityChangsha 410082People’s Republic of China Singapore Institute of Manufacturing Technology(SIM Tech) Agency for ScienceTechnology and Research(A∗STAR)5 Cleantech LoopSingapore 636732Singapore Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055People’s Republic of China Institute of Materials Research German Aerospace Center(DLR)Linder Höhe51147 CologneGermany Centre for Advanced Materials and Manufacturing Edith Cowan University270 Joondalup DriveJoondalupPerthWestern Australia 6027Australia Department of Materials Science and Engineering University of CaliforniaLos AngelesCA 900095United States of America Leibniz Institute for Materials Engineering-IWT Badgasteiner Str.328359 BremenGermany Faculty of Production Engineering University of BremenBadgasteiner Str.128359 BremenGermany Key Laboratory of Hunan Province of Equipment Safety Service Technology under Extreme Environment University of South ChinaHengyangPeople’s Republic of China RWTH Aachen University Metallic Structures and Materials Systems for Aerospace EngineeringD-52062 AachenGermany

Titanium(Ti)alloys are widely used in high-tech fields like aerospace and biomedical *** additive manufacturing(LAM),as an innovative technology,is the key driver for the development of Ti *** the significant advancements in LAM of Ti alloys,there remain challenges that need further research and development *** recap the potential of LAM high-performance Ti alloy,this article systematically reviews LAM Ti alloys with up-to-date information on process,materials,and *** feasible solutions to advance LAM Ti alloys are reviewed,including intelligent process parameters optimization,LAM process innovation with auxiliary fields and novel Ti alloys customization for *** auxiliary energy fields(***,acoustic,mechanical deformation and magnetic fields)can affect the melt pool dynamics and solidification behaviour during LAM of Ti alloys,altering microstructures and mechanical *** kinds of novel Ti alloys customized for LAM,like peritecticα-Ti,eutectoid(α+β)-Ti,hybrid(α+β)-Ti,isomorphousβ-Ti and eutecticβ-Ti alloys are reviewed in ***,machine learning in accelerating the LAM process optimization and new materials development is also *** review summarizes the material properties and performance envelops and benchmarks the research achievements in LAM of Ti *** addition,the perspectives and further trends in LAM of Ti alloys are also highlighted.

关键词： additive manufacturing titanium alloys auxiliary field machine learning aerospace materials lightweight materials novel alloys

A calibration and compensation method for an industrial robot with high accuracy harmonic reducers

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Science China(Technological Sciences) 2024年第3期67卷 725-739页

作者： ZHAO yiyang LIU Xun CAO JiaBin LIU Jinyu XU yan yan WeiXin School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China College of Computer and Control Engineering Northeast Forestry UniversityHarbin 150040China

Industrial serial robots need high stiffness to keep absolute pose accuracy and meet the requirements in practical applications. However, the weak stiffness feature of robot joints and the payloads affected on robot end-effector, which will also increase the pose error of robot. Especially, the existing calibration methods often consider under no-payload condition without discussing the payload state. In this paper, we report a new industrial serial robot composed by a new harmonic reducer: Model-y, based on high accuracy and high stiffness, and a kinematic parameter calibration algorithm which is based on a harmonic reducer forcedeformation model. To decrease the accuracy effects of payload, an iterative calibration method for kinematic parameters with payload situation was proposed. Simulation and experiments are conducted to verify the effectiveness of the proposed calibration method using the self-developed industrial serial robot. The results show a remarkably improved accuracy in absolute position and orientation with the robot's payload range. The position mean error has 70% decreased to 0.1 mm and the orientation mean error diminished to less than 0.01° after calibration with compensation. Additionally, online linear and circular tests are carried out to evaluate the position error of the robot during large-scale spatial and low-speed continuous movement. The accuracy is consistent with the previous calibration results, indicating the effectiveness and advantages of the proposed strategy in this article.

关键词： industrial serial robot Model-y harmonic calibration stiffness model online compensation

Priority effects of forbs arriving early:the role of root interaction and asymmetric competition

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Ecological Processes 2024年第1期13卷 53-65页

作者： Xiaohong yan Xiliang Li Ke Jin Institute of Grassland Research Chinese Academy of Agricultural Sciences

Background The priority effect of plant arrival is a key driver of community assembly and ecosystem succession during the restoration of degraded plant communities. However, the significance of the arrival order of different plant functional groups and their interactions with community assemblies remains unclear. Using a phytotron experiment with three fully crossed factors, we investigated the underlying mechanisms of priority effects and their relationships with the biomass and biodiversity effects in mixed plant communities by manipulating the order of arrival of species, isolation of roots, and removal of specific *** The results showed that the strength and direction of priority effects were influenced by arrival order, root interactions, asymmetric competition among species, and their interactions. The identities of early and late-sown species also determined the magnitude of priority effects. The priority effects were stronger in grass-first(24.76%) and legume-first communities(24.48%) than in forb-first communities. The pot biomass of the different priority treatments was highest in grass-first(5.85 g), followed by legume-first(3.94 g) and forb-first(2.48 g). The order of arrival in the mixture significantly affected the net biodiversity effects(P y dominance effects. The community had lower overall biomass when forbs were sown first, whereas the species grown later had fewer costs with an increased overall net benefit for the resulting *** Our results emphasize that root interactions and asymmetric competition are vital determinants of order-specific priority effects in community assemblies. In addition, the importance of the priority effect of forbs sown first is related to community assembly, which may be a key determinant in successfully establishing a highly diverse community in the early stages of restoration. Species with weak competition should be considered in the early stage of community ass

关键词： Community assembly Order of arrival Overyielding Plant functional group Root isolation

Model-driven path planning for robotic plasma cutting of branch pipe with single y-groove based on pipe-rotating scheme

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Advances in Manufacturing 2024年第1期12卷 94-107页

作者： yan Liu Qiu Tang Xin-Cheng Tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in *** improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single ***,it summarizes the intersection forms and introduces a dual-pipe intersection *** on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single y-groove is ***,a novel mathematical model for plasma radius and taper compensation is ***,the compensation model and groove model are integrated by establishing movable ***,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is *** the established models and moving frames,the planned path description of cutting robot is provided in this novel *** accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation