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An Intelligent Ellipsoid Calibration Method Based on the Grey Wolf Algorithm for Magnetic Compass

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Journal of Bionic Engineering 2021年第2期18卷 453-461页

作者： Xusheng lei Xiaoyu z.ang Yank.n Hao School of the Instrumentation Science and Opto-Electronic Engineering Beihang UniversityBeijing 100191China

With the measurement of the Earth’s magnetic field,magnetic compass can provide high frequency heading ***,it suffers from local magnetic *** intelligent ellipsoid calibration method based on the grey wolf is proposed to generate optimal parameters for magnetic compass to generate high performance heading *** the analysis of the projection relationship among the navigation coordinate frame,the body frame and the local horiz.ntal frame,the heading ellipsoid equation is ***,an improved grey wolf algorithm is proposed to find optimiz.tion solution in a large solution *** the improvement of the convergence factor and the evolutionary mechanism,the improved grey wolf algorithm can generate optimiz.d solution for heading ellipsoid *** effectiveness of the proposed method has been verified by a series of vehicle and flight *** experimental results show that the proposed method can eliminate errors caused by sensor defects,hard-iron interference,and soft-iron interference *** heading error generated by the magnetic compass is less than 0.2162 degree in real flight tests.

关键词： magnetic compass ellipsoid parameters grey wolf algorithm error model

Soft Tissue Deformation Modeling in the Procedure of Needle Insertion:A k.iging‑Based Method

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Chinese Journal of Mechanical Engineering 2022年第3期35卷 187-199页

作者： Yong lei Murong Li Dedong Gao State k.y Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China School of Mechanical Engineering Qinghai UniversityXining 810016China

The simulation and planning system(SPS)requires accurate and real-time feedback.regarding the deformation of soft tissues during the needle insertion *** mechanical-based models such as the finite element method(FEM)are widely used to compute the deformations of soft ***,it is difficult for the FEM or other methods to find a balance between an acceptable image fidelity and real-time deformation feedback.due to their complex material properties,geometries and interaction *** this paper,a k.iging-based method is applied to model the soft tissue deformation to strik. a balance between the accuracy and efficiency of deformation *** combinations of regression and correlation functions are compared regarding their ability to predict the maximum deformations of ten characteristic mark.rs at a fixed insertion *** results suggest that a first order regression function with Gaussian correlation functions can best fit the results of the ground *** functional response of the k.iging-based method is utiliz.d to model the dynamic deformations of mark.rs at a series of needle insertion *** feasibility of the method is verified by investigating the adaptation to step *** with the ground truth of the finite element(FE)results,the maximum residual is less than 0.92 mm in the Y direction and 0.31 mm in the X *** results suggest that the k.iging metamodel provides real-time deformation feedback.for a target and an obstacle to a SPS.

关键词： k.iging metamodel Needle insertion Real-time simulator Soft tissue deformation

Spherical Pack.ng Superlattices in Self-Assembly of Homogenous Soft Matter:Progresses and Potentials

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Chinese Journal of Polymer Science 2023年第5期41卷 607-620,I0005页

作者： Yuchu Liu Huanyu lei Qing-Yun Guo Xianyou Liu Xinghan Li Yuean Wu Weiyi Li Wei z.ang Geng Xin Liu Xiao-Yun Yan Stephen z.D.Cheng South China Advanced Institute for Soft Matter Science and Technology School of Molecular Science and EngineeringSouth China University of TechnologyGuangzhou 510640China School of Polymer Science and Polymer Engineering The University of AkronAkron OH 44325-3909USA State k.y Laboratory for Modification of Chemical Fibers and Polymer Materials Center for Advanced Low-dimension MaterialsCollege of Material Science and EngineeringDonghua UniversityShanghai 201620China

The construction of complex superlattices using homogenous soft matter has great potential for the bottom-up fabrication of complex,nanoscale *** topic is not only interested in scientific exploring for new concepts of supramolecular crystals with nanometer in siz.s,which is about thousand times larger in volumes than those of normal crystals,but also practically important to provide construction principles of metamaterials which are artificially structured materials for controlling and manipulating light,sound,and other physical *** systems have fast assembly k.netics and convenient processing procedures,mak.ng them ideal for large-scale superlattice *** this perspective,we focus on recent developments in the construction of complex spherical pack.ng superlattices using homogenous soft *** discuss the general mechanism of those formations of supramolecular motifs and provide an overview of the spherical pack.ng superlattices self-assembled by homogenous soft matters based on different volume ***,we outline the potentials of utiliz.ng this approach in constructing novel superlattices as well as its future challenges.

关键词： Soft matter Self-assembly Spherical pack.ng phases Superlattice Bottom-up construction

Outsourcing or Not? The OEMrs Better Collecting Mode under Cap-and-Trade Regulation

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Journal of Systems Science and Systems Engineering 2021年第2期30卷 151-177页

作者： lei Yang Caixia Hao Yijuan Hu Department of Electronic Business South China University of TechnologyGuangzhou 510006China Guangz.ou Automobile Group Motor CO. LTDGuangzhou 511434China

Many original equipment manufacturers(OEMs)carry out collecting operations by themselves or a third *** of the existing research papers in the literature consider the collecting mode selection problem from an economic ***,in practice,the firm's collecting decisions can be affected by the carbon policies at *** paper aims to bridge the gap in research on remanufacturing supply chain by tak.ng the effects of cap-and-trade regulation into *** models are established to study the quantity and price decisions under different collecting *** find that the OEM reaps more profits in the OEM collecting mode than the third-party collecting mode when collection cost is ***,the third party has lower collection cost,and the third-party collecting mode may mak. the OEM more *** an environmental perspective,with high collection cost,the third party collecting mode can reduce the carbon emissions unless the cost of new products and the emissions intensity are *** addition,when the collection cost is low but the quantity of remanufacturing products is restricted by that of new products,the third party collecting mode may increase the carbon *** addition,the implementation of cap-and-trade regulation can always reduce carbon emissions,and it may increase the OEM's profits if consumers preference for remanufactured products is small.

关键词： Remanufacturing collection decision carbon emissions cap-and-trade regulation

The fundamental plane relation of early-type galaxies:environmental dependence

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Research in Astronomy and Astrophysics 2015年第5期15卷 651-662页

作者： lei Hou Yu Wang Department of Astronomy University of Science and Technology of China

Using a sample of 70 793 early-type galaxies from SDSS DR7, we study the environmental dependence of the fundamental plane relation. With the help of the galaxy group catalog based on SDSS DR7, we calculate the fundamental planes in different dark.matter halo mass bins for both central and satellite galaxies. We find the environmental dependence of the fundamental plane coefficients is similar in the g, r, i and z.bands. The environmental dependence for central and satellite galaxies is significantly different. Although the fundamental plane coefficients for centrals vary systematically with the halo mass, those of satellites are similar in different halo mass bins. The discrepancy between centrals and satellites is significant in small halos, but negligible in the largest halo mass bins. These results remain the same when we only k.ep red galaxies, or galaxies with b/a 〉 0.6, or galaxies in a specific radius range in the sample. After the correction for the sk. back.round, the results are still similar. We suggest that the different environmental effects of the halo mass on centrals and satellites may arise from their different quenching processes.

关键词： galaxies elliptical and lenticular -- galaxies halo -- galaxies statistics

Feature extraction of wood-hole defects using wavelet-based ultrasonic testing

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Journal of Forestry Research 2017年第2期28卷 395-402页

作者： Huiming Yang lei Yu Northeast Forestry University Harbin 150040People's Republic of China

The primary bottleneck.to extracting wood defects during ultrasonic testing is the accuracy of identifying the wood defects. The wavelet energy moment was used to extract defect features of artificial wood holes drilled into 120 elm samples that differed in the number of holes to verify the validity of the method. Wavelet energy moment can reflect the distribution of energy along the time axis and the amount of energy in each frequency band,which can effectively extract the energy distribution characteristics of signals in each frequency band; therefore,wavelet energy moment can replace the wavelet frequency band energy and constitute wood defect feature vectors. A principal component analysis was used to normaliz. and reduce the dimension of the feature vectors. A total of 16 principal component features were then obtained, which can effectively extract the defect features of the different number of holes in the elm samples.

关键词： wavelet defects ultrasonic extracting replace validity identifying verify processed bottleneck

Surfaces with p_g= q = 1, k.2=6 and Non-birational Bicanonical Maps

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Acta Mathematica Sinica,English Series 2019年第3期35卷 321-337页

作者： Yong HU lei z.ANG School of Mathematics Korea Institute for Advanced Study School of Mathematical Science University of Science and Technology of China

Let S be a smooth minimal projective surface of general type with p_g(S) = q(S) = 1,k.S^2= 6. We prove that the degree of the bicanonical map of S is 1 or 2. So if S has non-birational bicanonical map, then it is a do... 详细信息

关键词： Bicanonical map algebraic surface albanese map

Long-term Correlations and Extreme Wind Speed Estimations

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Advances in Atmospheric Sciences 2019年第10期36卷 1121-1128页

作者： lei LIU Fei HU State k.y Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric University of Chinese Academy of Sciences Beijing 100049 China

In this paper, we use fluctuation analysis to study statistical correlations in wind speed time series. Each time series used here was recorded hourly over 40 years. The fluctuation functions of wind speed time series were found to scale with a universal exponent approximating to 0.7, which means that the wind speed time series are long-term correlated. In the classical method of extreme estimations, data are commonly assumed to be independent (without correlations). This assumption will lead to an overestimation if data are long-term correlated. We thus propose a simple method to improve extreme wind speed estimations based on correlation analysis. In our method, extreme wind speeds are obtained by simply scaling the mean return period in the classical method. The scaling ratio is an analytic function of the scaling exponent in the fluctuation analysis.

关键词： extreme wind speed fluctuation analysis generaliz.d Pareto distribution long-term correlation

A Humidity-Powered Soft Robot with Fast Rolling Locomotion

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Research 2022年第4期2022卷 97-106页

作者： lei Fu Weiqiang z.ao Jiayao Ma Mingyuan Yang Xinmeng Liu lei z.ang Yan Chen School of Mechanical Engineering Tianjin UniversityTianjin 300350China k.y Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300350China Department of Biochemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Frontier Science Center for Synthetic Biology and k.y Laboratory of Systems Bioengineering(MOE) Tianjin UniversityTianjin300350China

A range of soft robotic systems have recently been developed that use soft,flexible materials and respond to environmental *** greatest challenge in their design is the integration of the actuator,energy sources,and body of robots while achieving fast locomotion and well-defined programmable *** work.presents such a design that operates under constant conditions without the need for an externally modulated *** using a humidity-sensitive agarose film and overcoming the isotropic and random bending of the film,the robot,which we call the Hydrollbot,harnesses energy from evaporation for spontaneous and continuous fast self-rolling locomotion with a programmable trajectory in a constant-humidity ***,the geometric parameters of the film were fine-tuned to maximiz. the rolling speed,and the optimised hydrollbot is capable of carrying a payload up to 100%of its own *** ability to self-propel fast under constant conditions with programmable trajectories will confer practical advantages to this robot in the applications for sensors,medical robots,actuation,etc.

关键词： robot Robot humidity