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Optimal obstacle avoidance via distributed consensus algorithms with communication delay

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Journal of Systems Engineering and Electronics 2016年第6期27卷 1272-1282页

作者： Jingliang Sun chunsheng liu College of Automation Engineering Nanjing University of Aeronautics and Astronautics

A consensus problem of multi-agent system subject to the communication delay with fixed and switching topologies as well as optimal obstacle avoidance is investigated. An innovative non-quadratic obstacle avoidance cost function is designed from an inverse optimal control perspective and a novel dynamic potential field whose vectors are rotating around the obstacle is introduced to avoid obstacles. The asymptotic stability condition of dynamical networks based on the Lyapunov-Krasovskii function is obtained via a linear matrix inequality (LMI) formulation. Finally, numerical examples are presented to show the effectiveness of the proposed theoretical results. © 2016 Beijing Institute of Aerospace Information.

关键词： Asymptotic stability Collision avoidance Cost functions Inverse problems Linear matrix inequalities

Robust fault detection for a class of nonlinear network control system with communication delay

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Journal of Systems Engineering and Electronics 2009年第5期20卷 1024-1030页

作者： Ai Qiangyu liu chunsheng Jiang Bin Coll. of Automation Engineering Nanjing Univ. of Aeronautics and Astronautics Nanjing 210016 P. R. China

To investigate a class of nonlinear network control system, a robust fault diagnosis method is presented based on the robust state observer. To access the objective that the designed robust filter is maximally tolerant to disturbances and sensitive to fault, the robustness and stability properties of the fault diagnosis scheme are established rigorously. Using the residual vector, a fault tolerant controller is established in order to guarantee the stability of the closed-loop system, and the controller law can be obtained by solving a set of linear matrix inequalities. Then, some relevant sufficient conditions for the existence of a solution are given by applying Lyapunov stability theory. Finally, a simulation example is performed to show the effectiveness of the proposed approach.

关键词： nonlinear network control systems robust fault detection observer linear matrix inequality.

Research on a novel restoration algorithm of turbulence-degraded images with alternant iterations

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Journal of Systems Engineering and Electronics 2006年第3期17卷 477-482页

作者： liu chunsheng Hong Hanyu Zhang Tianxu Inst. for Pattern Recognition and AI State Key Laboratory of Image Processing and Intelligent Control Huazhong Univ. of Science and Technology Wuhan 430074 P. R. China

A new restoration algorithm based on double loops and alternant iterations is proposed to restore the object image effectively from a few frames of turbulence-degraded images, Based on the double loops, the iterative relations for estimating the turbulent point spread function PSF and object image alternately are derived. The restoration experiments have been made on computers, showing that the proposed algorithm can obtain the optimal estimations of the object and the point spread function, with the feasibility and practicality of the proposed algorithm being convincing.

关键词： turbulence-degraded image image restoration double loops alternant iterations.

Extended state observer based smooth switching control for tilt-rotor aircraft

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Journal of Systems Engineering and Electronics 2020年第4期31卷 815-825页

作者： ZOU Yiru liu chunsheng LU Ke School of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211100China Science&Technology on Rotorcraft Aeromechanics Laboratory China Helicopter Research and Development InstituteJingdezhen 333001China

A tilt-rotor aircraft has three flight modes: helicopter mode, airplane mode and conversion mode. Unlike the traditional aircraft, the tilt-rotor aircraft, which combines the characteristics of helicopters and fixed-wing aircraft, is a complex multi-body system with the violent variation of the aerodynamic parameters. For these characteristics, a new smooth switching control scheme is provided for the tilt-rotor aircraft. First, the reference commands for airspeed and nacelle angles are calculated by analyzing the conversion corridor and the conversion path. Subsequently, based on the finite-time switching theorem, an average dwell time condition is designed to guarantee the stability in the switching process. Besides, considering the state vibrations and bumps may appear in switching points, the fuzzy weighted logic is employed to improve the system transient performance. For disturbance rejection, three extended state observers are designed separately to estimate the disturbances in the switched systems. Compared with the traditional auto disturbance rejection control and proportion integration differentiation control, this method overcomes the conservatism of wasting the whole model information. The control performances of robustness and smoothness are verified with simulation, which shows that the new smooth switching control scheme is more targeted and superior than the traditional design method.

关键词： tilt-rotor aircraft switching control extended state observer(ESO) smooth switching

The antiviral and antimicrobial activities of licorice, a widely-used Chinese herb

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Acta Pharmaceutica Sinica B 2015年第4期5卷 310-315页

作者： Liqiang Wang Rui Yang Bochuan Yuan Ying liu chunsheng liu School of Chinese Pharmacy Beijing University of Chinese Medicine

Licorice is a common herb which has been used in traditional Chinese medicine for *** than 20 triterpenoids and nearly 300 flavonoids have been isolated from licorice. Recent studies have shown that these metabolites possess many pharmacological activities, such as antiviral,antimicrobial, anti-inflammatory, antitumor and other activities. This paper provides a summary of the antiviral and antimicrobial activities of licorice. The active components and the possible mechanisms for these activities are summarized in detail. This review will be helpful for the further studies of licorice for its potential therapeutic effects as an antiviral or an antimicrobial agent.

关键词： Licorice Antiviral Antimicrobial Glycyrrhizin Glycyrrhetinic acid Chalcone

Zero-Sum Differential Games for Nonlinear Systems Using Adaptive Dynamic Programming with Input Constraint 36

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Zero-Sum Differential Games for Nonlinear Systems Using Adap...

Full sexual maturity-cycle exposure to environmentally relevant concentrations of 17β-estradiol decreases reproductive capacity of zebrafish

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作者： Jingliang Sun chunsheng liu College of Automation Engineering Nanjing University of Aeronautics and Astronautics

ISBN: (纸本)9781538629185

In this paper, the zero-sum differential game problem for a class of nonlinear system with input constraints is investigated via adaptive dynamic programming（ADP）. A suitable non-quadratic functional is utilized to embed the control constraints into the differential game problem. Then, the Nash equilibrium solution is found by solving the constrained Hamilton-Jacobi-Isaacs（HJI） equation. The single critic network is constructed to approximate the solution of associated HJI equation online. A robustifying control term is added to the controller to eliminate the effect of residual error, leading to the asymptotically stability of the closed-loop system. Simulation results verify the effectiveness of proposed method by using a simple nonlinear system.

关键词： differential game adaptive dynamic programming asymptotically stability input constraints

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Journal of Environmental Sciences 2024年第3期137卷 580-592页

作者： Yongkang Zhang Yuanjun Jiang Qian Sun Meng Li Sheng Chen Jingyu Liang chunsheng liu College of Fisheries Huazhong Agricultural UniversityWuhan 430070China School of Environmental Studies China University of GeosciencesWuhan 430074China

17β-Estradiol(E2)has been widely detected in natural water and treatment with E2 induces potential endocrine disrupting effects in ***,effects on fish fecundity and steroid system after treatment with environmentally relevant concentrations of E2 for the full sexual maturation cycle remain *** this study,zebrafish were treatment with 0,10 or100 ng/L E2 from embryo to adult stage,and effects on gonadal development and differentiation,steroid hormone levels,transcription of genes associated with the hypothalamic-pituitary-gonadal-liver(HPG)axis in adults and fertilization rate of offspring were *** results showed that treatment with E2 lead to increased number of feminization in *** females,E2 decreased cumulative amount of spawning and inhibited the maturation of *** males,E2 inhibited the maturation and motility of sperm,as well as decreased the movement speed of *** adverse effects on sperm might be responsible for the reduced fertilization observed in *** addition,treatment with E2 changed the levels of steroid hormones in zebrafish gonad and altered the transcriptional levels of genes associated with HPG axis,which is responsible for the regulation of germ cells maturation and gonadal development in ***,these results suggested that treatment with environmentally relevant concentrations of E2 for the full sexual maturity cycle resulted in adverse effects on reproduction in zebrafish.

关键词： Environmental estrogen Zebrafish Fecundity Gonadal development Endocrine disruption

De novo biosynthesis of liquiritin in Saccharomyces cerevisiae

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Acta Pharmaceutica Sinica B 2020年第4期10卷 711-721页

作者： Yan Yin Yanpeng Li Dan Jiang Xianan Zhang Wei Gao chunsheng liu School of Chinese Pharmacy Beijing University of Chinese MedicineBeijing 102488China School of Traditional Chinese Medicine Capital Medical UniversityBeijing 100069China School of Pharmaceutical Sciences Advanced Innovation Center for Human Brain ProtectionCapital Medical UniversityBeijing 100069China Pharmacy Department Beijing Longfu HospitalBeijing 100010China

Liquiritigenin(LG),isoliquiritigenin(Iso-LG),together with their respective glycoside derivatives liquiritin(LN)and isoliquiritin(Iso-LN),are the main active flavonoids of Glycyrrhiza uralensis,which is arguably the most widely used medicinal plant with enormous demand on the market,including Chinese medicine prescriptions,preparations,health care products and even *** studies have shown that these ingredients have broad medicinal value,including anti-cancer and antiinflammatory *** the biosynthetic pathway of glycyrrhizin,a triterpenoid component from ***,has been fully analyzed,little attention has been paid to the biosynthesis of the flavonoids of this *** obtain the enzyme-coding genes responsible for the biosynthesis of LN,analysis and screening were carried out by combining genome and comparative transcriptome database searches of *** and homologous genes of known flavonoid biosynthesis *** catalytic functions of candidate genes were determined by in vitro or in vivo *** work characterized the complete biosynthetic pathway of LN and achieved the de novo biosynthesis of liquiritin in Saccharomyces cerevisiae using endogenous yeast metabolites as precursors and cofactors for the first time,which provides a possibility for the economical and sustainable production and application of *** flavonoids through synthetic biology.

关键词： Glycyrrhiza uralensis Liquiritin Isoliquiritin Liquiritigenin Isoliquiritigenin Heterologous synthesis Saccharomyces cerevisiae

Cloning and characterization of the gene encoding β-amyrin synthase in the glycyrrhizic acid biosynthetic pathway in Glycyrrhiza uralensis

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Acta Pharmaceutica Sinica B 2013年第6期3卷 416-424页

作者： Honghao Chen Ying liu Xiaoqin Zhang Xinjie Zhan chunsheng liu School of Chinese Pharmacy Beijing University of Chinese MedicineBeijing 100102China

Glycyrrhiza uralensis is considered to be one of the most important herbs in traditional Chinese medicine due to its numerous pharmacological effects particularly its ability to relieve cough and act as a *** on previous research,these effects are mediated by a number of active ingredients,especially glycyrrhizic acid(GA).In the present study,a gene encodingβ-amyrin synthase(β-AS)involved in GA biosynthesis in *** has been cloned and expressed in Saccharomyces *** cloned enzyme showed similar activity to native enzymes isolated from other Glycyrrhiza species to catalyze the conversion of 2,3-oxidosqualene intoβ-*** fact theβ-AS gene is particularly important in the GA biosynthetic pathway in *** complete sequence of the enzyme was determined and a phylogenetic tree based on theβ-AS gene of *** and 20 other species was *** showed that Glycyrrhiza glabra had the closest kinship with *** results of this work will be useful in determining how to improve the efficacy of *** by improving its GA content and in exploring the biosynthesis of GA in vitro.

关键词： β-Amyrin synthase Glycyrrhiza uralensis Glycyrrhizic acid Molecular cloning Heterologous expression GC–MS