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基于决策树的空间拦截器姿态控制

北京航空航天大学学报 2006年第10期32卷 1163-1167,1192页

作者：全权蔡开元北京航空航天大学自动化科学与电气工程学院北京100083

拦截器的发动机为带脉冲型发动机,从而限定了作动器的输出集.对于该拦截器的姿态控制,提出了基于决策树的控制方法.它是通过搜索决策树代价最小的路径做出控制决策,该控制思想非常类似棋手博弈的思想.提出的剪枝方案降低了决策树的计算... 详细信息

拦截器的发动机为带脉冲型发动机,从而限定了作动器的输出集.对于该拦截器的姿态控制,提出了基于决策树的控制方法.它是通过搜索决策树代价最小的路径做出控制决策,该控制思想非常类似棋手博弈的思想.提出的剪枝方案降低了决策树的计算复杂度.通过仿真实验说明:基于决策树的控制具有一定的智能;不同剪枝方案产生不同的控制效果;该方法较好地解决了输入受到约束、非线性和耦合的多输入多输出控制问题,并且在满足控制精度前提下可减少发动机切换次数和燃料消耗.

关键词：预测控制系统树姿态控制

Experimental warming shifts coupling of carbon and nitrogen cycles in an alpine meadow

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Journal of Plant Ecology 2021年第3期14卷 541-554页

作者： Song Wang quan quan Cheng Meng Weinan Chen Yiqi Luo Shuli Niu Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Center for Ecosystem Science and Society Northern Arizona UniversityFlagstaffAZ 86011USA

Aims Terrestrial ecosystem carbon(C)uptake is remarkably regulated by nitrogen(N)availability in the ***,the coupling of C and N cycles,as reflected by C:N ratios in different components,has not been well explored in response to climate *** Here,we applied a data assimilation approach to assimilate 14 datasets collected from a warming experiment in an alpine meadow in China into a grassland ecosystem *** attempted to evaluate how experimental warming affects C and N coupling as indicated by constrained parameters under ambient and warming treatments *** Findings The results showed that warming increased soil N availability with decreased C:N ratio in soil labile C pool,leading to an increase in N uptake by ***,C input to leaf increased more than N,leading to an increase and a decrease in the C:N ratio in leaf and root,*** C:N ratio was decreased due to the increased N immobilization under high soil N availability or warming-accelerated decomposition of litter *** also increased C:N ratio of slow soil organic matter pool,suggesting a greater soil C sequestration *** most models usually use a fixed C:N ratio across different environments,the divergent shifts of C:N ratios under climate warming detected in this study could provide a useful benchmark for model parameterization and benefit models to predict C-N coupled responses to future climate change.

关键词： Bayesian probabilistic inversion Markov-Chain Monte-Carlo(MCMC) warming carbon and nitrogen cycles stoichiometry alpine meadow

Safety Assessment for Autonomous Aerial Refueling Based on Reachability Analysis

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Transactions of Nanjing University of Aeronautics and Astronautics 2021年第2期38卷 216-224页

作者： REN Jinrui MA Haibiao quan quan HANG Bin School of Automation Northwestern Polytechnical UniversityXi’an 710072P.R.China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191P.R.China

Autonomous aerial refueling(AAR)has demonstrated significant benefits to aviation by extending the aircraft range and *** is of significance to assess system safety for autonomous aerial *** this paper,the reachability analysis method is adopted to assess system *** to system uncertainties,the aerial refueling system can be considered as a stochastic ***,probabilistic reachability is *** there is a close relationship between reachability probability and collision probability,the collision probability of the AAR system is analyzed by using reachability analysis ***,the collision probability is accessed by using the Monte-Carlo experiment ***,simulations demonstrate the effectiveness of the proposed safety assessment method.

关键词： aerial refueling safety assessment collision probability probabilistic reachability Monte-Carlo method

A Survey of Repetitive Control for Nonlinear Systems

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Science Foundation in China 2010年第2期18卷 45-53页

作者： quan quan Kai-Yuan Cai Department of Automatic Control Beijing University of Aeronautics and AstronauticsBeijing 100191China

In aerospace engineering and industry, control tasks are often of a periodic nature,while repetitive control is especially suitable for tracking and rejection of periodic exogenous *** of limited research effort on nonlinear systems, we give a survey of repetitive control for nonlinear systems in this ***,a brief introduction of repetitive control is ***,after giving a brief overview of repetitive control for linear systems,this paper summarizes design methods and existing problems of repetitive control for nonlinear systems in ***,relationships between repetitive control and other control schemes are analyzed to recognize repetitive control from different aspects more insightfully.

关键词： Instrumentation and measurement Statistical physics and nonlinear systems

Improvement of Response Performance of Liquid Crystal Optical Devices by using a Low Viscosity Component

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Chinese Physics Letters 2011年第9期28卷 147-149页

作者： PENG Zeng-Hui LIU Yong-Gang YAO Li-Shuang CAO Zhao-Liang MU quan-quan HU Li-Fa LU Xing-Hai XUAN Li ZHANG Zhi-Yong State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033 Wuhan Polytechnic University Wuhan 430024

Difluorooxymethylene-bridged(CF2O)liquid crystal(LC)with low viscosity is prepared and used as a fast response LC *** the material is mixed with isothiocyanato LCs with high birefringence,the visco−elastic coefficient of the mixture decreases evidently and,accordingly,the response performance *** the concentration of CF2O LCs is about 7%,the LC mixture approximately maintains high birefringence and exhibits a fastest response performance that is 14%higher than that of pure isothiocyanato ***,the LC material and mixing method could find useful applications in optical devices.

关键词： material mixture

Protective effects of organic extracts of Alpinia oxyphylla against hydrogen peroxide-induced cvtotoxicitv in PC12 cells

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Neural Regeneration Research 2020年第4期15卷 682-689页

作者： Li-Hong Duan Meng Li Chun-Bao Wang Qing-Mei Wang quan-quan Liu Wan-Feng Shang Ya-Jin Shen Zhuo-Hua Lin Tong-Yang Sun Zheng-Zhi Wu Ying-Hong Li Yu-Long Wang Xun Luo Shenzhen Institute of Geriatrics ShenzhenGuangdong ProvinceChina Department of Rehabilitation the Second People’s Hospital of ShenzhenShenzhenGuangdong ProvinceChina Stroke Biological Recovery Laboratory Spaulding Rehabilitation HospitalHarvard Medical SchoolCharlestownMAUSA Department of Mechanical and Biomedical Engineering City University of Hong KongHong Kong Special Administrative RegionChina Department of Rehabilitation the First Affiliated Hospital of Shenzhen UniversityShenzhenGuangdong ProvinceChina School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhouGuangdong ProvinceChina School of Mechanical Engineering Guangxi University of Science and TechnologyLiuzhouGuangxi Zhuang Autonomous RegionChina Mingkai Smart Medical Robot Co. Ltd.ShenzhenGuangdong ProvinceChina Kerry Rehabilitation Medicine Research Institute ShenzhenGuangdong ProvinceChina

Alpinia oxyphylla,a traditional herb,is widely used for its neuroprotective,antioxidant and memory-improving ***,the neuroprotective mechanisms of action of its active ingredients are *** this study,we investigated the neuroprotective effects of various organic extracts of Alpinia oxyphylla on PC12 cells exposed to hydrogen peroxide-induced oxidative injury in *** oxyphylla was extracted three times with 95%ethanol(representing extracts 1–3).The third 95%ethanol extract was dried and resuspended in water,and then extracted successively with petroleum ether,ethyl acetate and n-butanol(representing extracts 4–6).The cell counting kit-8 assay and microscopy were used to evaluate cell viability and observe the morphology of PC12 *** protective effect of the three ethanol extracts(at tested concentrations of 50,100 and 200μg/mL)against cytotoxicity to PC12 cells increased in a concentration-dependent *** ethyl acetate,petroleum ether and n-butanol extracts(each tested at 100,150 and 200μg/mL)had neuroprotective effects as *** optimum effective concentration ranged from 50–200μg/mL,and the protective effect of the ethyl acetate extract was comparatively *** results demonstrate that organic extracts of Alpinia oxyphylla protect PC12 cells against apoptosis induced by hydrogen *** findings should help identify the bioactive neuroprotective components in Alpinia oxyphylla.

关键词： active ingredients Alpinia oxyphylla apoptosis ethanol crude extract fraction hydrogen peroxide nerve regeneration neuroprotective agent neuroprotective effects PC12 cells traditional herb

Air Traffic Network Generation for UAVs at a Low Altitude Based on Digital Maps

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Air Traffic Network Generation for UAVs at a Low Altitude Ba...

Advances in Research of Pharmacological Effects and Molecular Mechanisms of Daurisoline

第三十九届中国控制会议

作者： Xin He quan quan School of Automation Science and Electrical Engineering Beihang University

Unmanned Aerial Vehicle（UAV） has a rapid growth in recent years. An efficient air traffic system for UAVs working at a low altitude which is rich of obstacles is desired. However, as far as we know, the work on the generation of such an air traffic network at a low altitude lacks attention. It is expected to develop an algorithm in order to generate a traffic network automatically similar to the complex road traffic network by taking a matrix or image marked with obstacles as input. Considering those situations above, this paper addresses（i） automatic air traffic network generation that is suitable for UAVs working at a low altitude,（ii） several line segments（airlines） fitting for a curve, and（iii） a graph modeling. A simple experiment is also performed to show the effectiveness of the method proposed.

关键词： Air Traffic Network Generation Graph Modeling

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Medicinal Plant 2022年第3期13卷 87-91页

作者： quan quan Chenghao JIN College of Life Science and Technology Heilongjiang Bayi Agricultural University Daqing 163319 China

Daurisoline is an important bisbenzylisoquinoline alkaloid and mainly exists in the rhizome of Menispermum dauricum DC.,a plant of the family *** to its pharmacological effects such as anti-arrhythmia,anti-ischemia and anti-cancer,daurisoline has attracted wide attention of *** this paper,the pharmacological effects and action mechanism of daurisoline were reviewed in combination with relevant research literature,to provide a theoretical basis for the development and clinical application of daurisoline.

关键词： Daurisoline Pharmacological effects Calcium regulation Anticancer

基于自由运动一维标定物的多摄像机参数标定方法与实验

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控制理论与应用 2014年第8期31卷 1018-1024页

作者：付强全权蔡开元北京航空航天大学自动化科学与电气工程学院北京航空航天大学虚拟现实技术与系统国家重点实验室

一维标定方法易于实现且标定效率高,为了克服现有一维标定方法的一些不足,本文提出一种用一维标定物标定多摄像机内外参数的方法,首先进行两两标定,在此过程中,假定主点坐标近似已知而仅考虑畸变、焦距、旋转和平移等参数,接着利用基本... 详细信息

一维标定方法易于实现且标定效率高,为了克服现有一维标定方法的一些不足,本文提出一种用一维标定物标定多摄像机内外参数的方法,首先进行两两标定,在此过程中,假定主点坐标近似已知而仅考虑畸变、焦距、旋转和平移等参数,接着利用基本矩阵及一维标定物上特征点之间的几何约束,估计两摄像机的内外参数,两两标定完成后,采用Dijkstra最短路径法和捆绑调整对多摄像机系统进行全局标定(含主点坐标),仿真和真实实验表明本文的方法是切实有效的.

关键词：多摄像机内外参数标定一维标定物自由运动