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A Compensation Controller Based on a Nonlinear Wavelet Neural Network for Continuous Material Processing Operations

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Computers, Materials & Continua 2019年第7期61卷 379-397页

作者： chen Shen youping chen Bing chen Jingming Xie School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhanChina

Continuous material processing operations like printing and textiles manufacturing are conducted under highly variable conditions due to changes in the environment and/or in the materials being *** such,the processing parameters require robust real-time adjustment appropriate to the conditions of a nonlinear *** paper addresses this issue by presenting a hybrid feedforward-feedback nonlinear model predictive controller for continuous material processing *** adaptive feedback control strategy of the controller augments the standard feedforward control to ensure improved robustness and compensation for environmental disturbances and/or parameter ***,the controller can reduce the need for manual *** controller applies nonlinear generalized predictive control to generate an adaptive control signal for attaining robust performance.A wavelet-based neural network model is adopted as the prediction model with high prediction precision and time-frequency localization *** training is utilized to predict uncertain system dynamics by tuning the wavelet neural network parameters and the controller parameters *** performance of the controller algorithm is verified by both simulation,and in a real-time practical application involving a single-input single-output double-zone sliver drafting system used in textiles *** the simulation and practical results demonstrate an excellent control performance in terms of the mean thickness and coefficient of variation of output slivers,which verifies the effectiveness of this approach in improving the long-term uniformity of slivers.

关键词： Continuous material processing wavelet neural network(WNN) nonlinear generalized predictive control(NGPC) auto-leveling system

Sequential slip transfer of mixed-character dislocations across Σ3 coherent twin boundary in FCC metals: a concurrent atomistic-continuum study

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npj Computational Materials 2016年第1期2卷 247-255页

作者： Shuozhi Xu Liming Xiong youping chen David L McDowell Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaGAUSA Department of Aerospace Engineering Iowa State UniversityAmesIAUSA Department of Mechanical and Aerospace Engineering University of FloridaGainesvilleFLUSA School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGAUSA

Sequential slip transfer across grain boundaries(GB)has an important role in size-dependent propagation of plastic deformation in polycrystalline *** example,the Hall–Petch effect,which states that a smaller average grain size results in a higher yield stress,can be rationalised in terms of dislocation pile-ups against *** spite of extensive studies in modelling individual phases and grains using atomistic simulations,well-accepted criteria of slip transfer across GBs are still lacking,as well as models of predicting irreversible GB structure *** transfer is inherently multiscale since both the atomic structure of the boundary and the long-range fields of the dislocation pile-up come into *** this work,concurrent atomistic-continuum simulations are performed to study sequential slip transfer of a series of curved dislocations from a given pile-up onΣ3 coherent twin boundary(CTB)in Cu and Al,with dominant leading screw character at the site of interaction.A Frank-Read source is employed to nucleate dislocations *** is found that subject to a shear stress of 1.2 GPa,screw dislocations transfer into the twinned grain in Cu,but glide on the twin boundary plane in ***,four dislocation/CTB interaction modes are identified in Al,which are affected by(1)applied shear stress,(2)dislocation line length,and(3)dislocation line *** results elucidate the discrepancies between atomistic simulations and experimental observations of dislocation-GB reactions and highlight the importance of directly modeling sequential dislocation slip transfer reactions using fully 3D models.

关键词： grain boundary transfer

Decreasing productivity of pine forests on the southern edge of the Mongolian Plateau as indicated by tree rings

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Journal of Forestry Research 2024年第5期35卷 171-181页

作者： Zhuolan Shen Shijie Wang Feng chen Heli Zhang Xiaoen Zhao youping chen Mao Hu Yunnan Key Laboratory of International Rivers and Transboundary Eco‑Security Institute of International Rivers and Eco‑SecurityYunnan UniversityKunming 650500People’s Republic of China Southwest United Graduate School Kunming 650500People’s Republic of China Key Laboratory of Tree-Ring Physical and Chemical Research of China Meteorological Administration/Xinjiang Laboratory of Tree-Ring Ecology Institute of Desert MeteorologyChina Meteorological AdministrationÜrümqi 830002People’s Republic of China

Vegetation productivity on the southern edge of the Inner Mongolian Plateau,which plays a vital role in the ecological environment and in the arable and pasto-ral production in this region,can be characterized by the NDVI(normalized difference vegetation index).However,the observed NDVI data span only the last~40 *** growth of Pinus tabulaeformis *** strongly correlated with the NDVI,making it a valuable proxy for extend-ing the length of observed NDVI *** this study,we reconstructed an NDVI series for 1776–2021 for the Daqing Mountains,based on a tree-ring width *** reconstructed data accounted for 55%of the variance in the observed data,and its statistical characteristics and validation indicate that the reconstruction is *** correlation analysis demonstrated the consistency of climate signals in central Inner Mongolia in both the arable and pastoral *** results of superposed epoch analysis revealed a good temporal consistency between drought and flood events and the reconstructed NDVI sequence in this region.

关键词： Drought Semi-arid area Peru current Yinshan Mountains

Research on reconfigurable collaborative remote diagnosis system

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High Technology Letters 2006年第2期12卷 160-164页

作者：袁楚明 chen youping Zhang Guohui Zhou Zude National NC System Engineering Research Center School of Mechanical Science ＆ Engineering Huazhong University of Science and Technology Wuhan 430074 P.R. China

The function-layer model and working model of collaborative remote fault diagnosis system （FDS）, which includes three layers： task layer, collaboration layer and diagnosing layer, are proposed. The running mechanism of the system is discussed. A collaborative FDS may consist of several subsystems running at different places and the subsystem consists of several fimction modules. A structure centered on data-bus is adopted in subsystem. All the function modules in subsystem are encapsulated into software intelligent chips （SICs） and SIC can but connect with data-bus. So, it is feasible to reuse these diagnosis fimction modules and the structure of subsystem in different diagnosis applications. With the reconfigurable SICs, several different function modules can reconstruct quickly some different diagnosis subsystems in different combinations, and some subsystems can also reconfigure a specified collaborative FDS.

关键词： fault diagnosis system collaboration reconfiguration software intelligent chip

FORCE RIPPLE SUPPRESSION TECHNOLOGY FOR LINEAR MOTORS BASED ON BACK PROPAGATION NEURAL NETWORK

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Chinese Journal of Mechanical Engineering 2008年第2期21卷 13-16页

作者： ZHANG Dailin chen youping AI Wu ZHOU Zude KONG Ching Tom School of Mechanical Engineering Huazhong University of Science and Technology Wuhan 430074 China Institute of Precision EngTneering The Chinese University of Hong Kong Hong Kong China

Various force disturbances influence the thrust force of linear motors when a linear motor （LM） is running. Among all of force disturbances, the force ripple is the dominant while a linear motor runs in low speed. In order to suppress the force ripple, back propagation（BP） neural network is proposed to learn the function of the force ripple of linear motors, and the acquisition method of training samples is proposed based on a disturbance observer. An off-line BP neural network is used mainly because of its high running efficiency and the real-time requirement of the servo control system of a linear motor. By using the function, the force ripple is on-line compensated according to the position of the LM. The experimental results show that the force ripple is effectively suppressed by the compensation of the BP neural network.

关键词： Linear motor (LM) Back propagation(BP) algorithm Neural network Anti-disturbance technology

August–September Runoff Variation in the Kara Darya River Determined from Juniper(Juniperus turkestanica) Tree Rings in the Pamirs-Alai Mountains, Kyrgyzstan, Back to 1411 CE

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Acta Geologica Sinica(English Edition) 2020年第3期94卷 682-689页

作者： ZHANG Heli HE Qing chen Feng Dogdurbek CHONTOEV Rysbek SATYLKANOV Bakytbek ERMENBAEV chen youping Key Laboratory of Tree-ring Physical and Chemical Research of the Chinese Meteorological Administration/Xinjiang Laboratory of Tree-ring Ecology Institute of Desert MeteorologyChinese Meteorological AdministrationUrumqi 830002China Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security Institute of International Rivers and Eco-SecurityYunnan UniversityKunming 650500China Tien-Shan Mountain Scientific Center Institute of Water Problems and Hydro PowerNational Academy of Sciences of The Kyrgyz RepublicBishkekKyrgyzstan

A 606 year runoff reconstruction of the Kara Darya River was developed, based on the tree-ring width chronology of Turkestan juniper(Juniperus turkestanica) from the Pamir-Alai Mountains of Kyrgyzstan. Preliminary comparison between the snow cover variation and these climate/runoff reconstructions found that Central Asian snow cover may have strong associations with large-scale ocean-atmosphere-land circulations. The runoff reconstruction demonstrated that instrumental runoff was not representative of runoff over the past 606 years. The drought of the 1960 s-1990 s resulted in low runoff levels during the past 50 years;however, this probably does not represent a worst-case scenario for the Kara Darya because the runoff reconstruction showed additional extremely low runoff prior to the 20 th century. The reconstruction will provide a long-term perspective on runoff variation in the Kara Darya River basin, aid sustainable water resource management and be useful in guiding expectations of future variations and water resource planning.

关键词： tree rings runoff reconstruction snow cover Kara Darya River

Fuzzy-Immune PID Control for AMB Systems

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Wuhan University Journal of Natural Sciences 2006年第3期11卷 637-641页

作者： SU Yixin LI Xuan ZHOU Zude chen youping ZHANG Danhong School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 Hubei China School of Automation Wuhan University of Technology Wuhan 430070 Hubei China

In order to improve the dynamic performance of active magnetic hearing systems with highly nonlinear and naturally unstable dynamics, a new nonlinear fuzzy-immune proportional integral-derivative （PID） controller is proposed by combining the immune feedback law with linear PID con trol. This controller consists of a PID controller and a basic immune proportional controller in cascaded connection, the nonlinear function of the immune proportional controller is realized by using fuzzy reasoning. Simulation results demon strate that the active magnetic bearing system with the proposed controller has better dynamic performance and disturbance rejection ability than using the linear PID controller.

关键词： active magnetic bearings fuzzy reasoning artificial immune fuzzy-immune PID

A 217-year precipitation reconstruction in the Habahe area, Xinjiang, Northeast China

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Journal of Forestry Research 2024年第6期35卷 242-254页

作者： Heli Zhang youping chen Feng chen Lu Li Huaming Shang Daming He Shengxia Jiang Mao Hu Xiaoen Zhao Weipeng Yue Shijie Wang Honghua Cao Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security Institute of International Rivers and Eco-SecurityYunnan UniversityKunming 650500China Institute of Desert Meteorology China Meteorological Administration/Key Laboratory of Tree-Ring Physical and Chemical Research of China Meteorological Administration/Xinjiang Key Laboratory for Tree Ring EcologyÜrümqi 830002China Xinjiang Meteorological Observatory Ürümqi 830002China

Evaluating long-term changes in precipitation resources is important for accurate hydrological evaluation and forecasting,water security and rational allocation of water *** this purpose in the Xinjiang Habahe area,tree-ring specimens were collected from Picea obovata,Larix sibirica,and Betula platyphylla to establish a tree-ring width chronology,which was used to analyse a correlation with the average temperature and precipitation per month for *** on correlation coefficients for monthly temperature and precipitation with the chronology of tree-ring widths,radial tree growth was mainly restricted by precipitation,and tree-ring width chronology was significantly correlated with overall precipitation from the previous July to the next June(r=0.641,P<0.01).The above results were used to establish a transformation equation,and the overall precipitation from the previous July to the following June from 1800 to 2016 in Habahe was reconstructed after adjusted degrees of freedom,and obtain an explanatory rate of the variation up to 41.1%(40.0%).In addition to the reliability of the reconstructed values,the stability of the conversion function was determined via the“leave-one-out”method,which is commonly used in research on tree rings,and by cross-checking the conversion function with the reduced error value(RE),product mean test(t),with a sign test(ST).During the last 217 years,there were nine dry periods:1803-1829,1861-1865,1872-1885,1892-1905,1916-1923,1943-1954,1961-1966,1973-1981,and 2005-2011;and 12 wet periods:1830-1834,1836-1860,1866-1871,1886-1891,1906-1915,1925-1930,1934-1942,1955-1960,1967-1972,1982-1996,2000-2004,and *** of the reconstructions for neighboring regions and a spatial correlation analysis showed that the reconstructed sequence of the present precipitation data better represented the changes in precipitation in ***,a power spectrum analysis revealed that precipitation over the past 217 years in

关键词： Tree ring Chronology Climate response Reconstruction Comparison

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抓好重大选题提高期刊质量

中国科技期刊研究 2005年第2期16卷 217-218页

作者：陈幼平 <岩矿测试>编辑部

《岩矿测试》杂志通过各种途径,围绕前沿课题和国民经济建设需要进行选题,提高了该刊学术水平,扩大了期刊影响力。

关键词：选题期刊质量期刊影响力学术水平重大杂志国民经济建设大选扩大途径