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学者姓名：王民
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摘要 ：
With the development of space technology, the large scale space deployable antennas gradually become one of the key research themes of research. The basic requirements for large scale satellite antennas are the characteristics of light in weight and high in profile accuracy. The low-frequency and large-amplitude vibration of the large scale antennas is easily excited when working in an environment with zero gravity. In order to suppress the vibration of large scale deployable satellite antenna, a new type of damping mechanism with resetting capability is presented to improve the ability of vibration energy consumption and ensure the dynamic characteristics of the radial rib structure containing the presented profile accuracy of the antenna. The rod making up the deployment mechanism of the antennas is divided into two parts which connected by using the shape memory alloy (SMA) wires through guiding mechanism. Meanwhile, a metal rubber is fixed and pressed between two parts of the rod by SMA wires. The ability of the friction energy dissipation of the metal rubber is utilized to suppress the axial vibration of the rods. The super elasticity of the SMA wires is used to provide the restoring force for ensuring the dimensional stability of the rod. In this paper, the design principle of the axial self-resetting damping structure is introduced in detail. And, the dynamic characteristics of the radial rib structure containing the presented damping mechanism are investigated by using the software ANSYS. The simulation results show that the vibration amplitude of the radial rib of antennas has been reduced significantly. © Published under licence by IOP Publishing Ltd.
关键词 ：
Scales (weighing instruments) Scales (weighing instruments) Energy utilization Energy utilization Rubber Rubber Energy dissipation Energy dissipation Satellite antennas Satellite antennas Dynamics Dynamics Vibration control Vibration control Satellites Satellites Wire Wire Damping Damping Shape-memory alloy Shape-memory alloy
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| GB/T 7714 | Wang, Min , Liu, Jiaxing , Liu, Qinda et al. Research on Damping Mechanism with Resetting Capability for Axial Vibration Control of Satellite Antenna [C] . 2021 . |
| MLA | Wang, Min et al. "Research on Damping Mechanism with Resetting Capability for Axial Vibration Control of Satellite Antenna" . (2021) . |
| APA | Wang, Min , Liu, Jiaxing , Liu, Qinda , Zhao, Tingting , Zhang, Yunfei . Research on Damping Mechanism with Resetting Capability for Axial Vibration Control of Satellite Antenna . (2021) . |
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摘要 ：
高速滚珠丝杠副非赫兹接触应力计算
关键词 ：
接触应力 接触应力 最小余能原理 最小余能原理 赫兹接触 赫兹接触 共轭梯度法 共轭梯度法 滚珠丝杠副 滚珠丝杠副
引用：
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| GB/T 7714 | 王民 , 孙铁伟 , 董朝阳 et al. 高速滚珠丝杠副非赫兹接触应力计算 [J]. | 王民 , 2021 , 53 (2) : 178-186 . |
| MLA | 王民 et al. "高速滚珠丝杠副非赫兹接触应力计算" . | 王民 53 . 2 (2021) : 178-186 . |
| APA | 王民 , 孙铁伟 , 董朝阳 , 孔德顺 , 高相胜 , 工程科学与技术 . 高速滚珠丝杠副非赫兹接触应力计算 . | 王民 , 2021 , 53 (2) , 178-186 . |
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摘要 ：
It is well-known that second-order optimizer can accelerate the training of deep neural networks, however, the huge computation cost of second-order optimization makes it impractical to apply in real practice. In order to reduce the cost, many methods have been proposed to approximate a second-order matrix. Inspired by KFAC, we propose a novel Trace-based Hardware-driven layer-ORiented Natural Gradient Descent Computation method, called THOR, to make the second-order optimization applicable in the real application models. Specifically, we gradually increase the update interval and use the matrix trace to determine which blocks of Fisher Information Matrix (FIM) need to be updated. Moreover, by resorting the power of hardware, we have designed a hardware-driven approximation method for computing FIM to achieve better performance. To demonstrate the effectiveness of THOR, we have conducted extensive experiments. The results show that training ResNet-50 on ImageNet with THOR only takes 66.7 minutes to achieve a top-1 accuracy of 75.9 % under an 8 Ascend 910 environment with MindSpore, a new deep learning computing framework. Moreover, with more computational resources, THOR can only takes 2.7 minutes to 75.9 % with 256 Ascend 910.
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| GB/T 7714 | Chen, Mengyun , Gao, Kaixin , Liu, Xiaolei et al. THOR, Trace-Based Hardware-Driven Layer-Oriented Natural Gradient Descent Computation [C] . 2021 : 7046-7054 . |
| MLA | Chen, Mengyun et al. "THOR, Trace-Based Hardware-Driven Layer-Oriented Natural Gradient Descent Computation" . (2021) : 7046-7054 . |
| APA | Chen, Mengyun , Gao, Kaixin , Liu, Xiaolei , Wang, Zidong , Ni, Ningxi , Zhang, Qian et al. THOR, Trace-Based Hardware-Driven Layer-Oriented Natural Gradient Descent Computation . (2021) : 7046-7054 . |
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摘要 ：
Mild cognitive impairment (MCI) detection using magnetic resonance image (MRI), plays a crucial role in the treatment of dementia disease at an early stage. Deep learning architecture produces impressive results in such research. Algorithms require a large number of annotated datasets for training the model. In this study, we overcome this issue by using layer-wise transfer learning as well as tissue segmentation of brain images to diagnose the early stage of Alzheimer's disease (AD). In layer-wise transfer learning, we used the VGG architecture family with pre-trained weights. The proposed model segregates between normal control (NC), the early mild cognitive impairment (EMCI), the late mild cognitive impairment (LMCI), and the AD. In this paper, 85 NC patients, 70 EMCI, 70 LMCI, and 75 AD patients access form the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Tissue segmentation was applied on each subject to extract the gray matter (GM) tissue. In order to check the validity, the proposed method is tested on preprocessing data and achieved the highest rates of the classification accuracy on AD vs NC is 98.73%, also distinguish between EMCI vs LMCI patients testing accuracy 83.72%, whereas remaining classes accuracy is more than 80%. Finally, we provide a comparative analysis with other studies which shows that the proposed model outperformed the state-of-the-art models in terms of testing accuracy.
关键词 ：
Alzheimer’s disease Alzheimer’s disease Early diagnosis Early diagnosis Image classification Image classification Transfer learning Transfer learning
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| GB/T 7714 | Mehmood Atif , Yang Shuyuan , Feng Zhixi et al. A Transfer Learning Approach for Early Diagnosis of Alzheimer's Disease on MRI Images. [J]. | Neuroscience , 2021 , 460 : 43-52 . |
| MLA | Mehmood Atif et al. "A Transfer Learning Approach for Early Diagnosis of Alzheimer's Disease on MRI Images." . | Neuroscience 460 (2021) : 43-52 . |
| APA | Mehmood Atif , Yang Shuyuan , Feng Zhixi , Wang Min , Ahmad Al Smadi , Khan Rizwan et al. A Transfer Learning Approach for Early Diagnosis of Alzheimer's Disease on MRI Images. . | Neuroscience , 2021 , 460 , 43-52 . |
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摘要 ：
When the stress wave propagates through rock mass with different wave impedances on two sides. It shows different reflection tendencies compared with the traditional study of wave propagation. A characteristic line method combined with the displacement discontinuity model was proposed to study the wave reflection through such rock mass. The effects of incident frequency, joint stiffness and wave impedance ratio on the reflection coefficient were discussed. The results show that the reflection coefficient increases as the wave impedance ratio increases. The traditional study of wave reflection can be regarded as a special case of the present study when the wave impedance ratio equals 1.0. Moreover, the difference of reflection coefficients decreases as the incident frequency increases, while increases as the joint stiffness and wave impedance ratio increase when the wave impedance ratio is larger than 1.0. When the wave impedance ratio is smaller than 1.0, the difference of reflection coefficients increases firstly and then decreases with the increase of incident frequency and joint stiffness, while decreases as the wave impedance ratio increases. For the cases of large incident frequency or small joint stiffness, the effects of wave impedance ratio can be neglected for the approximated prediction of wave reflection.
关键词 ：
jointed rock mass jointed rock mass > > wave impedance ratio wave impedance ratio reflection coefficient<break reflection coefficient<break amplitude attenuation amplitude attenuation Wave reflection Wave reflection
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| GB/T 7714 | Wang, L. J. , Wu, C. Q. , Fan, L. F. et al. Investigation of wave reflection at the joint with different wave impedances on two sides [J]. | WAVES IN RANDOM AND COMPLEX MEDIA , 2021 . |
| MLA | Wang, L. J. et al. "Investigation of wave reflection at the joint with different wave impedances on two sides" . | WAVES IN RANDOM AND COMPLEX MEDIA (2021) . |
| APA | Wang, L. J. , Wu, C. Q. , Fan, L. F. , Wang, M. . Investigation of wave reflection at the joint with different wave impedances on two sides . | WAVES IN RANDOM AND COMPLEX MEDIA , 2021 . |
| 导入链接 | NoteExpress RIS BibTex |
摘要 ：
Ball screws are the indispensable machine tool components and, as such, influence the positional accuracy of machine tools. The accuracy stability of machine tools is affected by thermal deformation of ball screws resulting from the increase in temperature. Inspired by the distinctive artificial muscle heat behavior, a bio-inspired ball screw was proposed. The proposed ball screw was based on the inner-embedded carbon fiber-reinforced plastic (CFRP), which restrains the axial expansion through the thermal contraction of CFRP. Additionally, a thermal conductor was mounted between the screw shaft and CFRP to improve the thermal conduction condition. Furthermore, both the simulation analysis and comparative experiments were carried out to compare the bio-inspired ball screw with the standard one. Two working conditions were considered to evaluate the effectiveness of the novel design, primarily in terms of reducing thermal deformation. Both results show that the proposed approach is effective and can be applied to reduce the thermal deformation of ball screws.
关键词 ：
artificial muscles artificial muscles ball screw ball screw CFRP CFRP contraction contraction thermal deformation thermal deformation
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| GB/T 7714 | Gao, Xiangsheng , Zhang, Kuan , Wang, Min et al. Thermally stimulated artificial muscles: Bio-inspired approach to reduce thermal deformation of ball screws based on inner-embedded CFRP [J]. | REVIEWS ON ADVANCED MATERIALS SCIENCE , 2021 , 60 (1) : 541-552 . |
| MLA | Gao, Xiangsheng et al. "Thermally stimulated artificial muscles: Bio-inspired approach to reduce thermal deformation of ball screws based on inner-embedded CFRP" . | REVIEWS ON ADVANCED MATERIALS SCIENCE 60 . 1 (2021) : 541-552 . |
| APA | Gao, Xiangsheng , Zhang, Kuan , Wang, Min , Zan, Tao , Luo, Jiajun . Thermally stimulated artificial muscles: Bio-inspired approach to reduce thermal deformation of ball screws based on inner-embedded CFRP . | REVIEWS ON ADVANCED MATERIALS SCIENCE , 2021 , 60 (1) , 541-552 . |
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摘要 ：
Second-order optimization methods have the ability to accelerate convergence by modifying the gradient through the curvature matrix. There have been many attempts to use second-order optimization methods for training deep neural networks. In this work, inspired by diagonal approximations and factored approximations such as Kronecker-factored Approximate Curvature (KFAC), we propose a new approximation to the Fisher information matrix (FIM) called Trace-restricted Kronecker-factored Approximate Curvature (TKFAC), which can hold the certain trace relationship between the exact and the approximate FIM. In TKFAC, we decompose each block of the approximate FIM as a Kronecker product of two smaller matrices and scaled by a coefficient related to trace. We theoretically analyze TKFAC's approximation error and give an upper bound of it. We also propose a new damping technique for TKFAC on convolutional neural networks to maintain the superiority of second-order optimization methods during training. Experiments show that our method has better performance compared with several state-of-the-art algorithms on some deep network architectures.
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| GB/T 7714 | Gao, Kaixin , Liu, Xiaolei , Huang, Zhenghai et al. A Trace-restricted Kronecker-factored Approximation to Natural Gradient [C] . 2021 : 7519-7527 . |
| MLA | Gao, Kaixin et al. "A Trace-restricted Kronecker-factored Approximation to Natural Gradient" . (2021) : 7519-7527 . |
| APA | Gao, Kaixin , Liu, Xiaolei , Huang, Zhenghai , Wang, Min , Wang, Zidong , Xu, Dachuan et al. A Trace-restricted Kronecker-factored Approximation to Natural Gradient . (2021) : 7519-7527 . |
| 导入链接 | NoteExpress RIS BibTex |
摘要 ：
Bearing fault diagnosis that utilizes motor current has shown great potential for industrial application. For estimating fault sizes, this paper develop an electromechanical-magnetic coupling computational model of induction motor (IM) based on modified winding function approach (MWFA) in order to extract the fault-excited harmonic components and amplitudes in stator current. A new evaluating indicator FHD (Fault-excited Harmonic Distortion) is then proposed to describe the specific relation between fault sizes and severity of fault-excited harmonic distortion. The statistical results show that there is a fixed functional relation curve between FHD and fault sizes in different IM. Finally, an experimental IM with a known size built-in faulted bearing is investigated. The 1 mm artificial damage on outer raceway is recognized by calculating FHD (0.5636 in average) value and comparing with the simulated relation curve. The results validate the accuracy and robustness of the proposed approach in fault size estimation. © 2020
关键词 ：
Ball bearings Ball bearings Electric fault currents Electric fault currents Harmonic analysis Harmonic analysis Harmonic distortion Harmonic distortion Induction motors Induction motors Stators Stators
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| GB/T 7714 | Wang, Chen , Wang, Min , Yang, Bin et al. A novel methodology for fault size estimation of ball bearings using stator current signal [J]. | Measurement: Journal of the International Measurement Confederation , 2021 , 171 . |
| MLA | Wang, Chen et al. "A novel methodology for fault size estimation of ball bearings using stator current signal" . | Measurement: Journal of the International Measurement Confederation 171 (2021) . |
| APA | Wang, Chen , Wang, Min , Yang, Bin , Song, Kaiyu , Zhang, Yiling , Liu, Liming . A novel methodology for fault size estimation of ball bearings using stator current signal . | Measurement: Journal of the International Measurement Confederation , 2021 , 171 . |
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摘要 ：
Thermal error of ball screws seriously affects the machining precision of computerized numerical control (CNC) machine tools especially in high speed and precision machining. Compensation technology is one of the most effective methods to address the thermal issue, and the effect of compensation depends on the accuracy and robustness of the thermal error model. Traditional modeling approaches have major challenges in time series thermal error prediction. In this paper, a novel thermal error model based on long short-term memory (LSTM) neural network and particle swarm optimization (PSO) algorithm is proposed. A data-driven model based on LSTM neural network is established according to the time series collected data. The hyperparameters of LSTM neural network are optimized by PSO, and then a PSO-LSTM model is established to precisely predict the thermal error of ball screws. In order to verify the effectiveness and robustness of the proposed model, two thermal characteristic experiments based on step and random speed are conducted on a self-designed test bench. The results show that the PSO-LSTM model has higher accuracy compared with the radial basis function (RBF) model and back propagation (BP) model with high robustness. The proposed method can be implemented to predict the thermal error of ball screws and provide a foundation for thermal error compensation.
关键词 ：
Thermal error Thermal error PSO-LSTM PSO-LSTM Data-driven Data-driven Modeling Modeling Ball screw Ball screw
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| GB/T 7714 | Gao, Xiangsheng , Guo, Yueyang , Hanson, Dzonu Ambrose et al. Thermal error prediction of ball screws based on PSO-LSTM [J]. | INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY , 2021 , 116 (5-6) : 1721-1735 . |
| MLA | Gao, Xiangsheng et al. "Thermal error prediction of ball screws based on PSO-LSTM" . | INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 116 . 5-6 (2021) : 1721-1735 . |
| APA | Gao, Xiangsheng , Guo, Yueyang , Hanson, Dzonu Ambrose , Liu, Zhihao , Wang, Min , Zan, Tao . Thermal error prediction of ball screws based on PSO-LSTM . | INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY , 2021 , 116 (5-6) , 1721-1735 . |
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摘要 ：
In this paper, we discuss the superconvergence of the "interpolated" collocation solutions for weakly singular Volterra integral equations of the second kind. Based on the collocation solution u(h), two different interpolation postprocessing approximations of higher accuracy: I-2h(2m-1) u(h) based on the collocation points and I(2h)(m)u(h) based on the least square scheme are constructed, whose convergence order are the same as that of the iterated collocation solution. Such interpolation postprocessing methods are much simpler in computation. We further apply this interpolation postprocessing technique to hybrid collocation solutions and similar results are obtained. Numerical experiments are shown to demonstrate the efficiency of the interpolation postprocessing methods.
关键词 ：
Interpolation postprocessing Interpolation postprocessing Weakly singular kernels Weakly singular kernels Volterra integral equations Volterra integral equations Supercloseness Supercloseness Superconvergence Superconvergence Collocation Collocation Hybrid collocation Hybrid collocation
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| GB/T 7714 | Huang, Qiumei , Wang, Min . Superconvergence of interpolated collocation solutions for weakly singular Volterra integral equations of the second kind [J]. | COMPUTATIONAL & APPLIED MATHEMATICS , 2021 , 40 (3) . |
| MLA | Huang, Qiumei et al. "Superconvergence of interpolated collocation solutions for weakly singular Volterra integral equations of the second kind" . | COMPUTATIONAL & APPLIED MATHEMATICS 40 . 3 (2021) . |
| APA | Huang, Qiumei , Wang, Min . Superconvergence of interpolated collocation solutions for weakly singular Volterra integral equations of the second kind . | COMPUTATIONAL & APPLIED MATHEMATICS , 2021 , 40 (3) . |
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