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Multilayer perceptron neural network activated by adaptive Gaussian radial basis function and its application to predict lid-driven cavity flow

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Acta Mechanica Sinica 2021年第12期37卷 1757-1772页

作者： Qinghua Jiang Lailai Zhu chang Shu Vinothkumar Sekar Department of Mechanical Engineering National University of Singapore10 Kent Ridge CrescentSingapore 117576Singapore

To improve the performance of multilayer perceptron(MLP)neural networks activated by conventional activation functions,this paper presents a new MLP activated by univariate Gaussian radial basis functions(RBFs)with adaptive centers and widths,which is composed of more than one hidden *** the hidden layer of the RBF-activated MLP network(MLPRBF),the outputs of the preceding layer are first linearly transformed and then fed into the univariate Gaussian RBF,which exploits the highly nonlinear property of *** RBFs might address the issues of saturated outputs,low sensitivity,and vanishing gradients in MLPs activated by other prevailing nonlinear ***,we apply four MLP networks with the rectified linear unit(ReLU),sigmoid function(sigmoid),hyperbolic tangent function(tanh),and Gaussian RBF as the activation functions to approximate the one-dimensional(1D)sinusoidal function,the analytical solution of viscous Burgers’equation,and the two-dimensional(2D)steady lid-driven cavity *** the same network structure,MLP-RBF generally predicts more accurately and converges faster than the other ***-RBF using less hidden layers and/or neurons per layer can yield comparable or even higher approximation accuracy than other MLPs equipped with more layers or neurons.

关键词： Multilayer perceptron neural network Activation function Radial basis function Numerical approximation

“十四五”时期成渝地区青少年体育教育协同治理:现实意义、逻辑框架及目标路径

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体育研究与教育 2024年第5期39卷 17-23页

作者：何玲玲王常安西华师范大学成渝地区教育与经济社会协同发展研究中心四川南充637001 泸州市实验小学城西学四川泸州646000 吉利学院体育与健康学院四川成都641423

运用文献资料、专家访谈等方法,探讨了“十四五”时期成渝地区青少年体育教育协同治理的现实意义、逻辑框架及精准路径。研究认为:成渝地区青少年体育教育协同治理的现实意义是实现青少年体育教育协同发展目标、功能定位是增强青少年体... 详细信息

运用文献资料、专家访谈等方法,探讨了“十四五”时期成渝地区青少年体育教育协同治理的现实意义、逻辑框架及精准路径。研究认为:成渝地区青少年体育教育协同治理的现实意义是实现青少年体育教育协同发展目标、功能定位是增强青少年体育教育治理能力、本体定位是凸显青少年体育教育本体效能。协同治理理念重视整体协调发展,兼顾公平与效率;协同治理要素,促进多维高效发展,兼顾共享共治成果;协同治理方式,强化创新综合发展,兼备能效精准治理;协同治理机制,推动一体化治理,兼具融合创新发展共同构成其逻辑框架。本研究针对发展困境提出精准路径:形塑协同治理目标图景、重构协同治理层级形态、完善协同治理结构系统、构建协同治理共生机制。

关键词： “十四五”时期青少年体育教育协同治理成渝地区

STRUCTURE AND PROPERTIES OF COMPOSITE POLYURETHANE HOLLOW FIBER MEMBRANES

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Chinese Journal of Polymer Science 2005年第2期23卷 203-210页

作者： Xian-fengLi chang-faXiao KeyLaboratoryofHollowFiberMembraneMaterialsandMembraneProcess MinistryofEducationDepartmentofMaterialsScienceTianjinPolytechnicUniversityTianjin300160China

Composite polyurethane(PU)-SiO_2 hollow fiber membranes were successfully prepared via optimizing thetechnique of dry-jet wet spinning,and their pressure-responsibilities were confirmed by the relationships of pure water flux-transmembrane pressure(PWF-TP)for the first *** origin for this phenomenon was analyzed on the basis of membranestructure and material *** effects of SiO_2 content on the structure and properties of membrane were*** experimental results indicated that SiO_2 in membrane created a great many interfacial micro-voids andplayed an important role in pressure-responsibility,PWF and rejection of membrane:with the increase of SiO_2 content,theability of membrane recovery weakened,PWF increased,and rejection decreased slightly.

关键词： Polyurethane Silicon dioxide Composite hollow fiber membrane Pressure-responsibility.

Design of novel NiSiAlY alloys in marine salt-spray environment:PartⅠ.Al-Si-Y and Ni-Si-Y subsystems

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Journal of Materials Science & Technology 2021年第29期88卷 66-78页

作者： Kai Xu Keke chang Yong Du Liping Wang Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

MCrAlY(M=Ni,Co,NiCo)alloys have been widely used as a bond layer for thermal barrier coatings(TBCs).However;oxides form discontinuously on MCrAlY surface in the marine environment since Cr_(2)O_(3)can react with NaCl and H_(2)O at temperatures above 500℃.Replacing Cr with other alloying elements(such as Si)might prevent severe salt-spray corrosion *** save time and efforts in materials design of the Ni-Si-Al-Y system;we obtained the thermodynamic descriptions of the ternary compounds by coupling the CALPHAD(CALculation of PHAse Diagrams)approach and first-principles *** and eighteen ternary compounds were evaluated and calculated in the Al-Si-Y and Ni-Si-Y systems;*** diagrams of the two systems were depicted after a series of experimental Al/Ni-Si-RE(RE denotes rare earth elements,including La,Ce,Pr,Nd,Sm,Gd,Dy,Ho,and Er)systems being *** is found that the RE elements with the same reference states tend to form ternary compounds with the same crystal *** model-based descriptions are the basis for the research and development of novel NiSiAlY alloys in resisting high-temperature corrosion.

关键词： Ternary compounds NiSiAlY CALPHAD Formation enthalpy Rare earth elements

Computer-Assisted Detection of Colonic Polyps Using Improved Faster R-CNN

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Chinese Journal of Electronics 2019年第4期28卷 718-724页

作者： LI Jiangyun ZHANG Jie chang Dedan HU Yaojun School of Automation and Electrical Engineering University of Science and Technology Beijing Key Laboratory of Knowledge Automation for Industrial Processes Ministry of Education Department of Gastroenterology Fu Xing Hospital Capital Medical University

The deficiencies of existing polyp detection methods remain: i) They primarily depend on the manually extracted features and require considerable amounts of preprocessing. ii) Most traditional methods cannot specify the location of the polyps in colonoscopy images, especially for the polyps with variable size. In order to derive the improvement and lift the accuracy, we propose a novel and scalable detection algorithm based on deep neural networks—an improved Faster Regionbased Convolutional neural networks(Faster R-CNN)—by increasing the fusion of feature maps at different *** can be employed to detect and locate polyps, and even achieve a multi-object task for polyps in the *** experimental consequences demonstrate that the best version among improved algorithms achieves 97.13%accuracy on the CVC-ClinicDB database, overtaking the previous methods.

关键词： Colonic polyps Deep learning Improved Faster R-CNN Object detection

基于混沌粒子群卷积神经网络的配电设备异常辨识技术研究

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制造业自动化 2024年第6期46卷 139-145页

作者：常荣罗映辉郭锐云南电网有限责任公司玉溪供电局云南玉溪653100

针对当前配电设备异常辨识率低导致电力系统的稳定性和可靠性变低的问题,提出了一种基于混沌粒子群卷积神经网络的配电设备异常辨识方法。首先分析影响配电设备正常工作的因素,使用最大信息系数(Maximum Information Coefficient,MIC)... 详细信息

针对当前配电设备异常辨识率低导致电力系统的稳定性和可靠性变低的问题,提出了一种基于混沌粒子群卷积神经网络的配电设备异常辨识方法。首先分析影响配电设备正常工作的因素,使用最大信息系数(Maximum Information Coefficient,MIC)的方法选取和配电设备健康状态最相关的状态量;其次将选择出来的状态量作为卷积神经网络(Convolutional Neural Network,CNN)的输入,为了提高网络的训练效率和速度,使用改进粒子群算法(Particle Swarm Optimization,PSO),即混沌粒子群算法(Chaos Particle Swarm Optimization,CPSO)去训练网络参数,深度学习配电设备特征,网络输出为设备状态;最后经过实验进行验证,将方法和普通卷积神经网络以及普通粒子群优化的卷积神经网络相比,对于配电设备异常辨识的准确率分别提高了10.28%和6.43%,说明了方法的优越性。

关键词：配电设备异常辨识最大信息系数卷积神经网络混沌粒子群

Fine Doppler shift acquisition algorithm for BeiDou software receiver by a look-up table

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Journal of Systems Engineering and Electronics 2020年第3期31卷 612-625页

作者： QIU Wenqi ZENG Qingxi GAO chang LYU Chade State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130012China Non-destructive Detection and Monitoring Technology for High-speed Transportation Facilities Key Laboratory of Ministry of Industry and Information Technology Nanjing 211106China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China

The BeiDou software receiver uses the fast Fourier transform(FFT)to perform the *** Doppler shift estimation accuracy should be less than 500 Hz to ensure satellite signals to enter a locked state in the tracking *** the frequency step is usually 500 Hz or larger,the Doppler shift estimation accuracy cannot guarantee that satellite signals are brought into a stable tracking *** straightforward solutions consist in increasing the sampling time and using zero-padding to improve the frequency resolution of the ***,these solutions intensify the complexity and amount of *** contradiction between the acquisition accuracy and the computational load leads us to research for a more simple and effective algorithm,which achieves fine acquisition by a look-up *** coarse acquisition using the parallel frequency acquisition(PFA)algorithm,the proposed algorithm optimizes the Doppler shift estimation through the look-up table method based on the FFT results to improve the acquisition accuracy of the Doppler shift with a minimal additional computing *** the Doppler shift is within the queryable range of the table,the proposed algorithm can improve the Doppler shift estimation accuracy to 50 Hz for the BeiDou B1I signal.

关键词： fine acquisition fast Fourier transform(FFT) table look-up parallel frequency acquisition(PFA) BeiDou

黄河下游地区青贮-子粒双季玉米种植模式的热量资源可行性分析

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玉米科学 2024年第2期32卷 95-105页

作者：徐欣莹邵长秀龙步菊孙志刚董宛麟中国农业大学资源与环境学院北京100193 中国科学院地理科学与资源研究所北京100101 中国科学院大学资源与环境学院北京100049 中科山东东营地理研究院山东东营257000 中国气象局气象干部培训学院北京100081

为了解黄河下游地区的热量资源并设计青贮-子粒新型双季玉米种植模式,基于位于黄河下游灌区的中科院禹城综合试验站1961-2020年逐日平均气温资料,对玉米可能生长期日数、初始日序、终止日序、活动积温、有效积温的历史趋势变化特征以及... 详细信息

为了解黄河下游地区的热量资源并设计青贮-子粒新型双季玉米种植模式,基于位于黄河下游灌区的中科院禹城综合试验站1961-2020年逐日平均气温资料,对玉米可能生长期日数、初始日序、终止日序、活动积温、有效积温的历史趋势变化特征以及不同熟期青贮-子粒玉米的组合模式进行系统分析和预测,比较青贮-子粒新型双季玉米种植模式与传统双季玉米种植模式。结果表明,禹城地区玉米积温与可能生长期日数在近60年内的年际增加趋势显著。根据可利用热量资源与玉米品种熟期,禹城地区双季玉米适宜的种植模式为早熟青贮-早熟子粒玉米、早熟青贮-中熟子粒玉米和中熟青贮-早熟子粒玉米,夏播子粒玉米的可调整弹性播期有显著增加趋势。

关键词：青贮-子粒双季玉米积温热量资源

A new viewpoint and model of neural signal generation and transmission: Signal transmission on unmyelinated neurons

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Nano Research 2021年第3期14卷 590-600页

作者： Zuoxian Xiang Chuanxiang Tang Chao chang Guozhi Liu Innovation Laboratory of Terahertz Biophysics National Innovation Institute of Defense TechnologyBeijing100071China Department of Engineering Physics Tsinghua UniversityBeijing100084China

We establish a preliminary model of neural signal generation and transmission based on our previous research,and use this model to study signal transmission on unmyelinated *** our model,the characteristics of neural signals are studied both on a long-time and a short time *** the long-time scale,the model is consistent with the circuit *** the short time scale,the neural system exhibits a THz and infrared electromagnetic oscillation but the energy envelope curve of the rapidly oscillating signal varies *** addition,the numerical method is used to solve the equations of neural signal generation and transmission,and the effects of the temperature on signal transmission are *** is found that overly high and overly low temperatures are not conducive to the transmission of neural signals.

关键词： THz ion channel neuron signal generation and conduction unmyelinated neuron