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Theoretical, Numerical and Experimental Study on Synchronization of Three Identical Exciters in a Vibrating System

Chinese Journal of Mechanical Engineering 2013年第4期26卷 746-757页

作者： ZHANG Xueliang WEN Bangchun zhao chunyu School of Mechanical Engineering and Automation Northeastern University

The theory on synchronization of two exciters is more widely used in engineering, while that of more than two exciters is less considered. So it is of great significant to investigate synchronization of three exciters. Firstly by introducing the average method of modified small parameters, the dimensionless coupling equations(DCE) of three exciters are derived, which convert the problem of synchronization into that of existence and stability of zero solutions for the DCE and lead to the construction on criterions of synchronization and stability in the simplified form for three exciters. Then the synchronization criterion is discussed numerically, as well as the abilities of synchronization and stability, some results thereof indicate that the synchronization ability increases with the increase of the coupling moment among three exciters, but decreases with that of their phase differences. Finally, an experiment on synchronization with three exciters is carried out. Through the comparison and analysis of experimental data on phase differences among three exciters, responses of system, and phases of three exciters recorded by high-speed camera, the parameters of system satisfying the above two criterions can ensure the synchronous and stable operation of three exciters. As a result, the average method of modified small parameters can be used as a theoretical apparatus studying reasonably the synchronization mechanism of three exciters, it is also proved to be useful and feasible by numeric and experiment. The present research lays the foundation and guidance for the establishment of synchronization theory system with multi-exciter and engineering design.

关键词： synchronization vibrating system stability coupling dynamic double-equilibrium

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Synchronization of two coupled exciters in a vibrating system of spatial motion

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Acta Mechanica Sinica 2010年第3期26卷 477-493页

作者： chunyu zhao Hongtao Zhu Yimin Zhang Bangchun Wen School of Mechanical Engineering and Automation Northeastern University 110004 Shenyang China Faculty of Engineering University of Wollongong Wollongong NSW 2522 Australia

The paper proposes an analytical approach to investigate the synchronization of the two coupled exciters in a vibrating system of spatial motion. Introducing the distur- bance parameters for average angular velocity of two excit- ers, we deduce the non-dimensional coupling equations of angular velocities of two exciters, in which the inertia cou- pling matrix is symmetric and the stiffness coupling matrix is antisymmetric in a non-resonant vibrating system. The analysis of the coupling dynamic characteristic shows that the coupled cosine effect of the phase angles will cause the torque acting on two motors to limit the increase of phase difference between two exciters as well as sustain its sym- metry of two exciters during the running process. It physi- cally explains the peculiarity of self-synchronization of two exciters. The cosine effect of phase angles of the vibrations excited by each exciter will decrease its moment of inertia. The residual moment of inertia of each exciter represents its relative moment of inertia. The stability condition of synchro- nization of two exciters is that the relative non-dimensional moments of inertia of two exciters are all greater than zero and four times their product is greater than the square of their coefficient of coupled cosine effect of phase angles, which is equivalent to that the inertia coupling matrix is positive definite and all its elements are positive. The numeric results show that the structure of the vibrating system can ensure the stability condition of synchronous operation.

关键词： Frequency capture - StabilitySynchronization Vibrating system -Vibratory synchronization transmission

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Self-synchronization theory of dual motor driven vibration system with two-stage vibration isolation frame

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Applied Mathematics and Mechanics(English Edition) 2015年第2期36卷 265-278页

作者： He LI Dan LIU Lai JIANG chunyu zhao Bangchun WEN School of Mechanical Engineering and Automation Northeastern University

This paper studies self-synchronization and stability of a dual-motor driven vibration system with a two-stage vibration isolation frame. Oscillation amplitude of the material box large enough can be ensured on the vibration system in order to screen materials. Reduction of the dynamic load transmitted to the foundation can also be achieved for the vibration system. A Lagrange equation is used to set up the motion differential equations of the system, and a dimensionless coupled equation of the eccentric rotors is obtained using a method of modified average small parameter. According to the existence condition of zero solution in the dimensionless coupled equation of the eccentric rotors, the precondition for commencing self-synchronization motion is *** stability condition of self-synchronization is obtained based on the Routh-Hurwitz criterion. The theoretical analysis is validated by simulations and experiments.

关键词： self-synchronization vibration system stability vibration isolation

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Analysis of Enterprise Knowledge Sharing Barrier Based on ISM Knowledge Value Chain

Analysis of Enterprise Knowledge Sharing Barrier Based on IS...

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第25届中国控制与决策会议

作者： zhao chunyu Feng Shi Harbin University of Commerce

ISBN: (纸本)9781467355339

Knowledge value chain is important for enterprise sharing knowledge. The enterprise sharing knowledge is based on knowledge value chain that contains two subjects, one object, one environment and one goal, and the barrier factors are divided into such four aspects as subject, object, environment and goal. By establishing model of interpreting structural equation, the hierarchical relations among barrier factors of enterprise knowledge sharing are analyzed to recognize such influential forces as basis, root-cause, crucial-point;therefore, countermeasure are proposed.

关键词： Knowledge value chain Knowledge sharing barrier ISM

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Multi-Scheme Corrected Dynamic–Analogue Prediction of Summer Precipitation in Northeastern China Based on BCC_CSM

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Journal of Meteorological Research 2017年第6期31卷 1085-1095页

作者： Yihe FANG Haishan CHEN Zhiqiang GONG Fangshu XU chunyu zhao Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory on Climate and Environment Changeand School of Atmospheric SciencesNanjing University of Information Science&TechnologyNanjing 210044 Regional Climate Center of Shenyang Shenyang 110016 Laboratory for Climate Studies and Climate Monitoring and Diagnose National Climate CenterChina Meteorological AdministrationBeijing 100081 Liaoning Meteorological Service Center Shenyang 110016

Based on summer precipitation hindcasts for 1991-2013 produced by the Beijing Climate Center Climate System Model （BCC_CSM）, the relationship between precipitation prediction error in northeastern China （NEC） and global sea surface temperature is analyzed, and dynamic-analogue prediction is carried out to improve the summer precipitation prediction skill of BCC_CSM, through taking care of model historical analogue prediction error in the real-time output. Seven correction schemes such as the systematic bias correction, pure statistical correction, dynamic-analogue correction, and so on, are designed and compared. Independent hindcast results show that the 5-yr average anomaly correlation coefficient （ACC） of summer precipitation is respectively improved from -0. 13/0.15 to 0.16/0.24 for 2009-13/1991-95 when using the equally weighted dynamic-analogue correction in the BCC_CSM prediction, which takes the arithmetical mean of the correction based on regional average error and that on grid point error. In addition, probabilistic prediction using the results from the multiple correction schemes is also performed and it leads to further improved 5-yr average prediction accuracy.

关键词： summer precipitation northeastern China sea surface temperature El Ni?o–Southern Oscillation Beijing Climate Center Climate System Model dynamic–analogue correction probabilistic prediction

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Classification of Northeast China Cold Vortex Activity Paths in Early Summer Based on K-means Clustering and Their Climate Impact

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Advances in Atmospheric Sciences 2021年第3期38卷 400-412页

作者： Yihe FANG Haishan CHEN Yi LIN chunyu zhao Yitong LIN Fang ZHOU Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110016China Regional Climate Center of Shenyang Liaoning Province Meteorological AdministrationShenyang 110016China Key Opening Laboratory for Northeast China Cold Vortex Research China Meteorological AdministrationShenyang 110016China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/International Joint Research Laboratory on Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing 210044China Liaoning Provincial Meteorological Service Center Shenyang 110016China Climate Change Research Center Institute of Atmospheric Physicsand Nansen-Zhu International

The classification of the Northeast China Cold Vortex(NCCV)activity paths is an important way to analyze its characteristics in *** on the daily precipitation data of the northeastern China(NEC)region,and the atmospheric circulation field and temperature field data of ERA-Interim for every six hours,the NCCV processes during the early summer(June)seasons from 1979 to 2018 were objectively ***,the NCCV processes were classified using a machine learning method(k-means)according to the characteristic parameters of the activity path *** rationality of the classification results was verified from two aspects,as follows:(1)the atmospheric circulation configuration of the NCCV on various paths;and(2)its influences on the climate conditions in the *** obtained results showed that the activity paths of the NCCV could be divided into four types according to such characteristics as the generation origin,movement direction,and movement velocity of the *** included the generation-eastward movement type in the east of the Mongolia Plateau(eastward movement type or type A);generation-southeast longdistance movement type in the upstream of the Lena River(southeast long-distance movement type or type B);generationeastward less-movement type near Lake Baikal(eastward less-movement type or type C);and the generation-southward less-movement type in eastern Siberia(southward less-movement type or type D).There were obvious differences observed in the atmospheric circulation configuration and the climate impact of the NCCV on the four above-mentioned types of paths,which indicated that the classification results were reasonable.

关键词： northeastern China early summer Northeast China Cold Vortex classification of activity paths machine learning method k-means clustering high-pressure blocking

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Sub-Seasonal Predictability of the Northeast China Cold Vortex in BCC and ECMWF S2S Model Forecasts for 2006-2021

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Journal of Meteorological Research 2024年第3期38卷 453-468页

作者： Yiqiu YU Jie WU Yihe FANG chunyu zhao Zongjian KE Yitong LIN Liaoning Provincial Climate Centre Liaoning Provincial Meteorological AdministrationShenyang110166China Key Opening Laboratory for Northeast China Cold Vortex Research China Meteorological AdministrationShenyang110166China Panjin National Climate Observatory Panjin124000China China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreChina Meteorological AdministrationBeijing100081China Jilin Provincial Climate Centre Jilin Provincial Meteorological AdministrationChangchun130062China

As an important atmospheric circulation system in the mid-high latitudes of East Asia,the Northeast China cold vortex(NCCV)substantially influences weather and climate in this *** far,systematic assessment on the performance of numerical prediction of the NCCVs has not been carried *** on the Beijing Climate Centre(BCC)and the ECMWF model hindcast and forecast data that participated in the Sub-seasonal to Seasonal(S2S)Prediction Project,this study systematically examines the performance of both models in simulating and forecasting the NCCVs at the sub-seasonal *** results demonstrate that the two models can effectively capture the seasonal variations in the intensity,active days,and spatial distribution of NCCVs;however,the duration of NCCVs is shorter and the intensity is weaker in the models than in the *** analysis shows that the differences in the intensity and location of the East Asian subtropical westerly jet and the wave train pattern from North Atlantic to East Asia may be responsible for the deficient simulation of NCCV events in the S2S ***,in the deterministic forecasts,BCC and ECMWF provide skillful prediction on the anomalous numbers of NCCV days and intensity at a lead time of 4-5(5-6)pentads,and the skill limit of the ensemble mean is 1-2 pentads longer than that of individual *** the probabilistic forecasts of daily NCCV activities,BCC and ECMWF exhibit a forecasting skill of approximately 7 and 11 days,respectively;both models show seasonal dependency in the simulation performance and forecast skills of NCCV events,with better performance in winter than in *** results from this study provide helpful references for further improvement of the S2S prediction of NCCVs.

关键词： Northeast China cold vortex(NCCV) predictability sub-seasonal to seasonal(S2S)prediction deterministic forecast probabilistic forecast

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The Coordinated Influence of Indian Ocean Sea Surface Temperature and Arctic Sea Ice on Anomalous Northeast China Cold Vortex Activities with Different Paths during Late Summer

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Advances in Atmospheric Sciences 2023年第1期40卷 62-77页

作者： Yitong LIN Yihe FANG chunyu zhao Zhiqiang GONG Siqi YANG Yiqiu YU Regional Climate Center of Shenyang Liaoning Provincial Meteorological AdministrationShenyang 110016China Key Opening Laboratory for Northeast China Cold Vortex Research China Meteorological AdministrationShenyang 110016China College of Physics and Electronic Engineering Changshu Institute of TechnologyChangshu 215500China Laboratory for Climate Studies National Climate Research CenterChina Meteorological AdministrationBeijing 100081China Inner Mongolia Climate Center Hohhot 010051China

The Northeast China cold vortex(NCCV)during late summer(from July to August)is identified and classified into three types in terms of its movement path using machine *** relationships of the three types of NCCV intensity with atmospheric circulations in late summer,the sea surface temperature(SST),and Arctic sea ice concentration(SIC)in the preceding months,are *** sensitivity tests by the Community Atmosphere Model version 5.3(CAM5.3)are used to verify the statistical *** results show that the coordination pattern of East Asia-Pacific(EAP)and Lake Baikal high pressure forced by SST anomalies in the North Indian Ocean dipole mode(NIOD)during the preceding April and SIC anomalies in the Nansen Basin during the preceding June results in an intensity anomaly for the first type of *** the pattern of high pressure over the Urals and Okhotsk Sea and low pressure over Lake Baikal during late summer-which is forced by SST anomalies in the South Indian Ocean dipole mode(SIOD)in the preceding June and SIC anomalies in the Barents Sea in the preceding April-causes the intensity anomaly of the second *** third type is atypical and is not analyzed in *** tests,jointly forced by the SST and SIC in the preceding period,can well reproduce the *** contrast,the results forced separately by the SST and SIC are poor,indicating that the NCCV during late summer is likely influenced by the coordinated effects of both SST and SIC in the preceding months.

关键词： machine learning method Northeast China cold vortex path classification Indian Ocean sea surface temperature Arctic sea ice model sensitivity test

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Bias Analysis and Correction of Ground Surface Temperature Observations across China

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Journal of Meteorological Research 2020年第6期34卷 1324-1334页

作者： Yan CUI Wenhui XU Zijiang ZHOU chunyu zhao Yihui DING Xue AO Xiaoyu ZHOU Shenyang Regional Climate Center Liaoning Meteorological BureauShenyang 110166 National Meteorological Information Center China Meteorological AdministrationBeijing 100081 National Climate Center China Meteorological AdministrationBeijing 100081

Based on the ground surface temperature(GST)and snow surface temperature(SST)measurements during the period of adjustment from manual to automatic observation systems in China,the influence of observation methods on GST and its relationship with snow cover is *** is corrected by SST,and the correction effect is *** results show that,during the parallel observation period,the winter GSTs from automatic observations are generally higher than those from manual observations,with the automatically observed national daily GST 1.18°C *** adjustment has a greater impact on GSTs at 0200,0800,and 2000 Beijing Time(BT)than at 1400 BT,and it has the greatest impact in Northeast and Northwest China,with deviations of 5.24 and 2.09°C,*** GST deviation is closely related to the snow depth and annual snow *** average daily GST deviation increases at the rate of 0.66°C per 1-cm increase of snow depth when it is<15 cm,while it tends to be stable at around 10°C for snow depth over 15 *** GST deviation at a station is affected by its winter snow totals in Northeast and Northwest China,where the largest deviations are found where snow totals are all above 1000 *** the correction with SST,the mean deviation between the automatic and manual observations as well as the false trend can be effectively *** the correction,the mean deviation of daily GST decreases by 5.8°C,and its trend decreases from 1.87 to 0.65°C decade-1.

关键词： ground surface temperature(GST)in winter snow cover correction China

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Endovascular middle cerebral arterial occlusion in a nonhuman primate model of chronic stroke

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Neural Regeneration Research 2011年第8期6卷 629-634页

作者： Qiang Wang Tong Zhang chunyu zhao Bin Du Feng Gao Mei Wen Weijian Jiang Department of Neurorehabilitation Capital Medical University School of Rehabilitation Medicine Beijing Charity Hospital China RehabilitationResearch Center Beijing 100068 China

No study has reported the safety, effectiveness, and consistency of endovascular middle cerebral artery occlusion in a chronic cerebral ischemia model. Nor have studies verified the safest and most effective segment, or branch, in the embolic middle cerebral artery. In this experiment, cerebral infarction models were established at M1, and on the upper and lower trunks on the contralateral side of the handedness of rhesus monkeys by using endovascular intervention. The results confirmed a high animal survival rate in stroke models of middle cerebral artery upper trunk occlusion. There was pronounced paralysis at the acute phase, long-term upper extremity dysfunction at the chronic phase, and the models showed good repeatability and consistency. Thus, this study describes a safe and effective model of chronic stroke.

关键词： nonhuman primate animal model cerebral infarction chronic phase endovascular occlusion neural regeneration

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