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Chinese Journal of Aeronautics 2014年第4期27卷 964-976页

作者： geng jie Sheng Yongzhi Liu Xiangdong Key Laboratory for Intelligent Control&Decision of Complex Systems Beijing Institute of Technology School of Automation Beijing Institute of Technology

This paper proposes a finite-time robust flight controller, targeting for a reentry vehicle with blended aerodynamic surfaces and a reaction control system（RCS）. Firstly, a novel finite-time attitude controller is pointed out with the introduction of a nonsingular finite-time sliding mode manifold. The attitude tracking errors are mathematically proved to converge to zero within finite time which can be estimated. In order to improve the performance, a second-order finite-time sliding mode controller is further developed to effectively alleviate chattering without any deterioration of robustness and accuracy. Moreover, an optimization control allocation algorithm, using linear programming and a pulse-width pulse-frequency（PWPF） modulator, is designed to allocate torque commands for all the aerodynamic surface deflections and on–off switching-states of RCS *** are provided for the reentry vehicle considering uncertain parameters and external disturbances for practical purposes, and the results demonstrate the effectiveness and robustness of the attitude control system.

关键词： Chattering alleviation Control allocation Finite-time convergence Flight control systems Second-order sliding mode Singularity elimination Sliding mode control

Second-order time-varying sliding mode control for reentry vehicle

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International Journal of Intelligent Computing and Cybernetics 2013年第3期6卷 272-295页

作者： jie geng Yongzhi Sheng Xiangdong Liu Key Laboratory of Complex System Intelligent Control and Decision School of AutomationBeijing Institute of TechnologyMinistry of EducationBeijingPeople’s Republic of China

Purpose-The purpose of this paper is to design a global robust and continuous control scheme for the attitude tracking control problem of the reentry vehicle with parameter uncertainties and ***/methodology/approach-First,feedback linearization is applied to the model of reentry vehicle,resulting in three independent uncertain *** a new second-order time-varying sliding function is proposed,based on which a continuous second-order time-varying sliding mode control(SOTVSMC)law is proposed for each *** global robustness and convergence performance of the closed-loop reentry vehicle control system under the proposed control law are ***-Simulation is made for a reentry vehicle through the assumption that there is external disturbance to aerodynamic moment and the aerodynamic parameters as well as the atmospheric density are *** results verify the validity and robustness of the proposed ***/value-The SOTVSMC attitude controller based on feedback linearization is proposed for the reentry *** advantages of the proposed SOTVSMC are ***,the global second order sliding mode is established,which implies that the closed-loop system is global robust against matched parameter uncertainties and disturbances in ***,the chattering problem is significantly alleviated.

关键词： Flight control Nonlinear control Real-time systems Robust control Variable structure control

A Full-Newton Step Feasible IPM for Semidefinite Optimization Based on a Kernel Function with Linear Growth Term

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Wuhan University Journal of Natural Sciences 2020年第6期25卷 501-509页

作者： geng jie ZHANG Mingwang PANG Jinjuan Mathematics Department Anhui Institute of Information TechnologyWuhu 241000AnhuiChina College of Science China Three Gorges UniversityYichang 443002HubeiChina

In this paper,we propose and analyze a full-Newton step feasible interior-point algorithm for semidefinite optimization based on a kernel function with linear growth *** kernel function is used both for determining the search directions and for measuring the distance between the given iterate and theμ-center for the *** developing a new norm-based proximity measure and some technical results,we derive the iteration bound that coincides with the currently best known iteration bound for the algorithm with small-update *** our knowledge,this result is the first instance of full-Newton step feasible interior-point method for SDO which involving the kernel function.

关键词： semidefinite optimization interior-point algorithm kernel function iteration complexity

A Full-Newton Step Feasible Interior-Point Algorithm for the Special Weighted Linear Complementarity Problems Based on a Kernel Function

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Wuhan University Journal of Natural Sciences 2024年第1期29卷 29-37页

作者： geng jie ZHANG Mingwang ZHU Dechun Mathematics Department Anhui Institute of Information TechnologyWuhu 241000AnhuiChina College of Science China Three Gorges UniversityYichang 443002HubeiChina

In this paper,a new full-Newton step primal-dual interior-point algorithm for solving the special weighted linear complementarity problem is designed and *** algorithm employs a kernel function with a linear growth term to derive the search direction,and by introducing new technical results and selecting suitable parameters,we prove that the iteration bound of the algorithm is as good as best-known polynomial complexity of interior-point ***,numerical results illustrate the efficiency of the proposed method.

关键词： interior-point algorithm weighted linear complementarity problem full-Newton step kernel function iteration complexity

CD147 deficiency in T cells prevents thymic involution by inhibiting the EMT process in TECs in the presence of TGFβ

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Cellular & Molecular Immunology 2021年第1期18卷 171-181页

作者： Ruo Chen Ke Wang Zhuan Feng Ming-Yang Zhang Jiao Wu jie-jie geng Zhi-Nan Chen Department of Cell Biology College of Life Science and TechnologyJinan UniversityGuangdongChina National Translational Science Center for Molecular Medicine&Department of Cell Biology Fourth Military Medical UniversityShaanxiChina

Thymic involution during aging is a major cause of decreased T-cell production and reduced ***,we show that the loss of CD147 on T cells prevents thymic senescence,resulting in slowed shrinkage of the thymus with age and increased production of naive T *** phenotype is the result of slowing of the epithelial-mesenchymal transition(EMT)process in thymic epithelial cells(TECs),which eventually leads to reduced adipocyte *** an in vitro coculture system,we found that TGFβ is an important factor in the EMT process in TECs and that it can reduce the expression of E-cadherin through p-5mad2/FoxC2 ***,CD147 on T cells can accelerate the decline in E-cadherin expression by interacting with Annexin A2 on *** the presence of TGFβ,Annexin A2 and E-cadherin colocalize on ***,CD147 on T cells competitively binds to Annexin A2 on TECs,leading to the isolation of ***,the isolated E-cadherin is easily phosphorylated by phosphorylated Src kinase,the phosphorylation of which was induced by TGFβ,and finally,p-E-cadherin is ***,in the thymus,the interaction between T ceils and TECs contributes to thymic involution with *** this study,we illuminate the mechanism underlying the triggering of the EMT process in TECs and show that inhibiting TGFβ and/or CD147 may serve as a strategy to hinder age-related thymic involution.

关键词： CD147 TGFβ thymic involution EMT

Relative position fitting based control strategy for thruster point assembly mechanism of electric propulsion

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International Journal of Intelligent Computing and Cybernetics 2016年第1期9卷 69-82页

作者： Xiaohui Li jie geng Qiang Zhang Jing Sun Beijing Institute of Control Engineering BeijingChina

Purpose-Thruster point assembly mechanism(TPAM)of the electric propulsion system allows to adjust the thrust vector,sothat the thrust vectorisdirectedtothesatellitecenterof gravity(COG)during the satellite on-orbit working *** this way the impact of disturbance torque caused by deviation of the thrust vector from the satellite COG during thruster ignition can be ***,the control accuracy of satellite is influenced directly by the control accuracy of *** the other hand,the on-orbit application of TPAM is restricted to the on-orbit computer ***,the purpose of this paper is to design a control strategy for TPAM,and the strategy should not only be able to control the TPAM precisely but also be easily implemented by the on-board ***/methodology/approach-First,the structure and work principle of TPAM are discussed,and the mathematical model based on D-H coordinate system is built for *** the fitting methods are utilized to design the control strategy of *** position fitting-based control strategy and relative position fitting-based control strategy are designed,and the least squares algorithm is introduced for parameter ***-Simulations and tests are provided for the *** with the state-of-the-art PD controller,the proposed control strategy shows smaller overshoot and more simple *** experiment results are matched with the simulation results and both the experiment and simulation results show the validity of the proposed control *** implications-The designed control strategies can be used for the TPAM of some satellite’s electric propulsion ***/value-The mathematical model of the TPAM based on D-H coordinate system is *** absolute position fitting-based control strategy and relative position fitting-based control strategy are *** with existing methods,the two control strategies have more simple structure and smaller amoun

关键词： Control strategy Nonlinear control D-H coordinate system Fitting Thruster point assembly mechanism TPAM Electric propulsion system

SDRE based Optimal Time-Varying Sliding Mode Control for Re-entry Vehicle

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SDRE based Optimal Time-Varying Sliding Mode Control for Re-...

Second-Order Time-Varying Sliding Mode Control for Uncertain Systems

第25届中国控制与决策会议

作者： Liang Wang Yongzhi Sheng Xiangdong Liu jie geng School of Automation Beijing Institute of Technology Key laboratory for Intelligent Control & Decision of Complex Systems Beijing Institute of Technology

ISBN: (纸本)9781467355339

An optimal time-varying sliding mode controller based on SDRE approach is proposed in this paper for re-entry vehicle attitude control in the presence of parametric uncertainties and external disturbances. Firstly, an optimal time-varying sliding surface is obtained through the minimization of a given performance index function and the philosophy of time-varying sliding mode control. Subsequently, a discontinuous control law is designed for guaranteeing the existence of the sliding mode throughout the entire response of the system. Therefore, the global robustness can be ensured. Simulation example is finally given to illustrate the effectiveness of the proposed controller.

关键词： Re-entry vehicle Attitude control SDRE Optimal time-varying sliding mode control

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Second-Order Time-Varying Sliding Mode Control for Uncertain...

Simulation Research on a SVPWM Control Algorithm for a Four-Leg Active Power Filter

第25届中国控制与决策会议

作者： jie geng Yongzhi Sheng Xiangdong Liu Bing Liu School of Automation Beijing Institute of Technology Key Laboratory of Complex System Intelligent Control and Decision Ministry of Education

ISBN: (纸本)9781467355339

A novel second-order time-varying sliding mode control（SOTVSMC） law is proposed for the robust tracking control problem of nonlinear smooth single-input single-output（SISO） system with disturbance. The advantages of the proposed SOTVSMC are twofold. The global second order sliding mode is established, which implies that the closed-loop system is global robust against matched parameter uncertainties and disturbances. Meanwhile, the chattering problem is significantly alleviated. Then the parameter of the sliding mode is obtained by solving an optimal problem. Finally, the effectiveness and robustness of the control strategy is demonstrated by simulation results.

关键词： Sliding Mode Control Nonlinear Systems Global Second Order Sliding Phase Chattering Alleviation

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Journal of China University of Mining and Technology 2007年第4期17卷 590-594页

作者： ZHOU Juan WU Xiao-jie geng Yi-wen DAI Peng School of Information and Electrical Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

In this paper the topology of a four-leg shunt active-power filter (APF) is given. The APF compensates har-monic and reactive power in a three-phase four-wire system. The scheme adopted for control of the four-leg active power filter,a 3-Dimensional Pulse Width Modulation (PWM) technique,is presented. The theoretical deduction of a space vector PWM (SVPWM) algorithm is given in this paper. The paper also analyzes the distribution of the volt-age-space vector of the four-leg converter in αβγ coordinates and describes methods to determine the location of the voltage-space vector and to calculate duration time. Finally,the algorithm is implemented in simulation; the results show that the total harmonic distortion (THD) of the three phase-current waveforms is reduced. The neutral wire current,after compensation,is about 0 A showing that the topology of the four-leg shunt APF is feasible and the proposed scheme is effective.

关键词： three-phase four-wire system shunt active power filter 3-Dimensional space vector PWM

Water Role and Its Influence on Hydrogen Isotopic Composition of Natural Gas during Gas Generation

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Acta Geologica Sinica(English Edition) 2011年第5期85卷 1203-1210页

作者： Jijun LI Shuangfang LU Wei WU Haitao XUE Qingxia XU jie geng Yinghua YU College of Earth Sciences Northeast Petroleum University Daqing Heilongjiang 163318 China Luliang Operating District of Xinjiang Oilfield Company Karamay Xinjiang 834000 China Exploration and Development Research Institute Daqing Oilfield Company Ltd. Daqing Heilongjiang 163712 China

In order to discuss the role and influence of water during the generation of natural gas,the participation mechanism of water during the evolution of organic matter and its influences were *** addition,we carried out an anhydrous cracking experiment of oil extracted from the Feixianguan Formation source rock in a closed system,which led to the establishment of the kinetic models for describing carbon and hydrogen isotopic fractionation during gas generation from organic *** models were calibrated and then applied to the northeastern Sichuan *** combining a series of gas generation experiments from octadecane pyrolysis without water or with distilled water in varying mass proportions,several results were proved:(1) the hydrogen isotopic composition of natural gas becomes lighter with the participation of formation water;(2) we can quantitatively study the hydrogen isotopic fractionation with the kinetic model for describing carbon isotopic fractionation; (3) more abundant and reliable geological information can be obtained through the combined application of carbon and hydrogen isotopic indices.

关键词： natural gas formation water free radical carbonium ion carbon and hydrogen isotopic fractionation kinetics