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Self-supervised coarse-to-fine monocular depth estimation using a lightweight attention module

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Computational Visual Media 2022年第4期8卷 631-647页

作者： Yuanzhen Li fei Luo Chunxia xiao School of Computer Science Wuhan UniversityWuhan 430072China

Self-supervised monocular depth estimation has been widely investigated and applied in previous ***,existing methods suffer from texture-copy,depth drift,and incomplete *** is difficult for normal CNN networks to completely understand the relationship between the object and its surrounding ***,it is hard to design the depth smoothness loss to balance depth smoothness and *** address these issues,we propose a coarse-to-fine method with a normalized convolutional block attention module(NCBAM).In the coarse estimation stage,we incorporate the NCBAM into depth and pose networks to overcome the texture-copy and depth drift ***,we use a new network to refine the coarse depth guided by the color image and produce a structure-preserving depth result in the refinement *** method can produce results competitive with state-of-the-art *** experiments prove the effectiveness of our two-stage method using the NCBAM.

关键词： monocular depth estimation texture copy depth drift attention module

Efficient and Reliable Nanoindentation Simulation by Dislocation Loop Erasing Method

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Acta Mechanica Solida Sinica 2020年第5期33卷 586-599页

作者： fei Shuang Pan xiao Yilong Bai LNM Institute of MechanicsChinese Academy of SciencesBeijing100190China Department of Mechanical and Aerospace Engineering University of FloridaGainesvilleFL32611USA

Nanoindentation is a useful technique to measure material properties at microscopic ***,the intrinsically multiscale nature makes it challenging for large-scale simulations to be carried *** is shown that in molecular statics simulations of nanoindentation,the separated dislocation loops(SDLs)are trapped in simulation box which detrimentally affects the plastic behavior in the plastic zone(PZ);and the long-distance propagation of SDLs consumes much computational cost yet with little contribution to the variation of tip *** tackle the problem,the dislocation loop erasing(DLE)method is proposed in the work to alleviate the influence of artificial boundary conditions on the SDL–PZ interaction and improve simulation *** results indicate that the force–depth curves obtained from simulations with and without DLE are consistent with each other,while the method with DLE yields more reasonable results of microstructural evolution and shows better *** new method provides an alternative approach for large-scale molecular simulation of nanoindentation with reliable results and higher efficiency and also sheds lights on improving existing multiscale methods.

关键词： Nanoindentation Dislocation loops Boundary effects Molecular statics

Application of Deep Learning to Production Forecasting in Intelligent Agricultural Product Supply Chain

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Computers, Materials & Continua 2023年第3期74卷 6145-6159页

作者： xiao Ya Ma Jin Tong fei Jiang Min Xu Li mei Sun Qiu Yan Chen Department of Logistics Management and Engineering Nanning Normal UniversityNanning530023China Guangxi Key Lab of Human-Machine Interaction and Intelligent Decision Nanning Normal UniversityNanning530023China School of Management and Marketing Faculty of Business and LawTaylor’s UniversityKuala Lumpur47500Malaysia Graduate Department Yunnan Normal UniversityKunming650500China

Production prediction is an important factor influencing the realization of an intelligent agricultural supply *** an Internet of Things(IoT)environment,accurate yield prediction is one of the prerequisites for achieving an efficient response in an intelligent agricultural supply *** an example,this study applied a conventional prediction method and deep learning prediction model to predict the yield of a characteristic regional fruit(the Shatian pomelo)in a comparative *** root means square error(RMSE)values of regression analysis,exponential smoothing,grey prediction,grey neural network,support vector regression(SVR),and long short-term memory(LSTM)neural network methods were 53.715,6.707,18.440,1.580,and 1.436,*** these,the mean square error(MSE)values of the grey neural network,SVR,and LSTM neural network methods were 2.4979,31.652,and 2.0618,respectively;and theirRvalues were 0.99905,0.94,and 0.94501,*** results demonstrated that the RMSE of the deep learning model is generally lower than that of a traditional prediction model,and the prediction results are more *** prediction performance of the grey neural network was shown to be superior to that of SVR,and LSTM neural network,based on the comparison of parameters.

关键词： Internet of things intelligent agricultural supply chain deep learning production prediction

Rutile in HP Rocks from the Western Tianshan,China:Mineralogy and Its Economic Implications

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Journal of Earth Science 2018年第5期29卷 1049-1059页

作者： Wen Su Jilei Li Qian Mao Jun Gao Xin Liu fei Chen xiao-mei Ge State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Mineral Resources Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Beijing Institute of Geology for Mineral Resources Beijing 100012China

Rutile is a common Ti-bearing accessory mineral in high pressure （HP） metamorphic rocks of the western Tianshan. Distribution of rutile in the HP rocks varies from 0.5% in the greenschist to 30% in the rutile-bearing vein. Rutile can be subdivided into three groups based on the variation of trace elements： The first group has an averaged Zr content of 18 ppm-44 ppm and Hf content of 0.8 ppm-2.4 ppm, which correspond to occurrence of rutile from vein; the second group Zr of 59 ppm-63 ppm, Hf of 3.5 ppm-3.7 ppm; and the third group Zr of 150 ppm-160 ppm and Hf of 3.9 ppm, corresponding to rutile in the matrix of blueschist and eclogite, respectively. Rutile has been retrograded to ilmenite and titanite partly or completely, reducing the value of the ore. But rutile of HP rocks in the western Tianshan usually has the lowest content of uranium （〈1 ppm U）, which might become an attractive raw material for the Ti industry. Therefore, rutile-bearing HP rocks in the western Tianshan as a mineral resource will be the focus of considerable attention.

关键词： Ti resource rutile HP vein eclogite western Tianshan.

Extended DMPs Framework for Position and Decoupled Quaternion Learning and Generalization

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 227-239页

作者： Zhiwei Liao fei Zhao Gedong Jiang Xuesong mei State Key Laboratory for Manufacturing System Engineering Xi’an Jiaotong UniversityXi’an 710049China Shaanxi Key Laboratory of Intelligent Robots and School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China

Dynamic movement primitives(DMPs)as a robust and efcient framework has been studied widely for robot learning from *** DMPs framework mainly focuses on the movement learning in Cartesian or joint space,and can’t properly represent end-efector *** this paper,we present an extended DMPs framework(EDMPs)both in Cartesian space and 2-Dimensional(2D)sphere manifold for Quaternion-based orientation learning and *** mixture model and Gaussian mixture regression(GMM-GMR)are adopted as the initialization phase of EDMPs to handle multi-demonstrations and obtain their mean and ***,some evaluation indicators including reachability and similarity are defned to characterize the learning and generalization abilities of ***,a real-world experiment was conducted with human demonstrations,the endpoint poses of human arm were recorded and successfully transferred from human to the *** experimental results show that the absolute errors of the Cartesian and Riemannian space skills are less than 3.5 mm and 1.0°,*** Pearson’s correlation coefcients of the Cartesian and Riemannian space skills are mostly greater than *** developed EDMPs exhibits superior reachability and similarity for the multi-space skills’learning and *** research proposes a fused framework with EDMPs and GMM-GMR which has sufcient capability to handle the multi-space skills in multi-demonstrations.

关键词： Learning from demonstration Dynamic movement primitives 2D sphere manifold Gaussian mixture model Gaussian mixture regression Quaternion-based orientation

Inverse grain-size-dependent strain rate sensitivity of face-centered cubic high-entropy alloy

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Journal of Materials Science & Technology 2021年第27期86卷 251-259页

作者： Lili xiao Ping Huang fei Wang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an710049China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi'an Jiaotong UniversityXi’an710049China

It is well documented that the strain rate sensitivity(m)increases at refined grain size for face-centered cubic(FCC)metals and *** a series of nanoindentation testing,however,we experimentally demonstrated a striking departure from conventional FCC metals that Co Cr Fe Mn Ni high entropy alloy(HEA)with FCC lattice structure exhibits monotonously decreased m as grain size reduced fromμ30.3m to 7.2 ***,the apparent activation volume v*,which generally shows an opposite trend of m,exhibited the identical decreasing trend with reduced grain size as that of *** an unusual trend of m and its correlation with v*in the FCC HEA alloys can be understood by a distinct deformationmechanism-transitions and unique dislocation morphology evolution that differs from conventional FCC metals.

关键词： High entropy alloy Strain rate sensitivity Activation volume Deformation mechanism Wavy dislocation

Torque estimation for robotic joint with harmonic drive transmission based on system dynamic characteristics

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Journal of Systems Engineering and Electronics 2022年第6期33卷 1320-1331页

作者： ZHU Minghong xiao Shu YU fei Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China College of Intelligent Systems Science and Engineering Harbin Engineering UniversityHarbin 150001China College of Mathematical Sciences Harbin Engineering UniversityHarbin 150001China

In the applications of joint control and robot movement,the joint torque estimation has been treated as an effective technique and widely *** are made to analyze the kinematic and compliance model of the robot joint with harmonic drive to acquire high precision torque *** analyzing the structures of the harmonic drive and experiment apparatus,a scheme of the proposed joint torque estimation method based on both the dynamic characteristics and unscented Kalman filter(UKF)is designed and *** on research and scheme,torque estimation methods in view of only harmonic drive compliance model and compliance model with the Kalman filter are simulated as guidance and reference to promote the research on the torque estimation ***,a promoted torque estimation method depending on both harmonic drive compliance model and UKF is designed,and simulation results compared with the measurements of a commercial torque sensor,have verified the effectiveness of the proposed method.

关键词： harmonic drive torque estimation compliance model unscented Kalman filter(UKF)

Numerical research on adverse effect of muzzle flow formed by muzzle brake considering secondary combustion

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Defence Technology（防务技术） 2021年第4期17卷 1178-1189页

作者： Peng-fei Li xiao-bing Zhang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing210094PR China

The simulation of the artillery interior and intermediate ballistics problem is performed to investigate the influence of a gas dynamics device,muzzle brake,on the muzzle hazard phenomena,such as flash and blast *** correlation of the chemical reactions with the characteristics of the muzzle flow field is analyzed by the simulation for a further understanding of the secondary combustion phenomenon of the muzzle *** novel structure of muzzle flow caused by the muzzle brake is presented by the simultaneous solution of the interior ballistics model and multi-species Navier-Stokes equations in order to analyze the influence of the muzzle brake structure on the chemical *** secondary combustion of the muzzle flow due to the oxygen-supplement chemical reactions is obtained by the chemical reaction kinetic *** interaction of the blast waves released from the muzzle brake is illustrated in detail and the mechanism of the formation of muzzle flash is *** research provides a reference for the studies on the suppression of the muzzle flash.

关键词： Muzzle flow Muzzle brake Secondary combustion Chemical reaction

Modeling the redshift and energy distributions of fast radio bursts

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Research in Astronomy and Astrophysics 2017年第2期17卷 22-28页

作者： xiao-Feng Cao Ming xiao fei xiao Department of Physics and Engineering Hubei University of Education Wuhan 430205 China

Abstract Fast radio bursts （FRBs） are one of the most mysterious astronomical phenomena nowadays. The identification of their origin requires more observations in the future and, importantly, deep un- derstandings of the existing observational data. By fitting the redshift and energy distributions of 15 Parkes FRBs, we try to derive their intrinsic energy function and the cosmic evolution of their burst rates. Specifically, while the energy function is assumed as usual to have a single-power-law form, the burst rates are considered to be proportional to the cosmic star formation rates by a redshift-dependent coefficient. Some plausible fittings are obtained, which indicate the power-law assumptions are feasible and effective. The values of the power-law indices could be used to independently constrain candidate FRB models, although parameter degeneracies still exist.

关键词： radio continuum general