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Dynamic Event-Triggered consensus control for Input constrained Multi-Agent Systems With a Designable Minimum Inter-Event Time

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IEEE/cAA Journal of Automatica Sinica 2024年第3期11卷 649-660页

作者： Meilin Li Yue Long Tieshan Li Hongjing Liang c.L.Philip chen the School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731China IEEE the Yangtze Delta Region Institute University of Electronic Science and Technology of ChinaHuzhou 313000 the Laboratory of Electromagnetic Space cognition and Intelligent control Beijing 100089China the School of computer Science and Engineering South China University of TechnologyGuangzhou 510006

This paper investigates the consensus control of multi-agent systems(MASs) with constrained input using the dynamic event-triggered mechanism(ETM).consider the MASs with small-scale networks where a centralized dynamic ETM with global information of the MASs is first ***,a distributed dynamic ETM which only uses local information is developed for the MASs with large-scale *** is shown that the semi-global consensus of the MASs can be achieved by the designed bounded control protocol where the Zeno phenomenon is eliminated by a designable minimum inter-event *** addition,it is easier to find a trade-off between the convergence rate and the minimum inter-event time by an adjustable ***,the results are extended to regional consensus of the MASs with the bounded control *** simulations show the effectiveness of the proposed approach.

关键词： constrained input designable minimum inter-event time directed communication topology dynamic event-triggered mechanism MASs consensus control

Adaptive neural network control of a 2-DOF helicopter system considering input constraints and global prescribed performance

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Science china(Information Sciences) 2024年第7期67卷 224-239页

作者： Zhijia ZHAO Jiale WU Zhijie LIU We HE c.L.Philip chen School of Mechanical and Electrical Engineering Guangzhou University School of Intelligence Science and Technology and Key Laboratory of Intelligent Bionic Unmanned Systems of Ministry of Education University of Science and Technology Beijing School of computer Science and Engineering South China University of Technology Pazhou Lab

In this study, an adaptive neural network(NN) control is proposed for nonlinear two-degree-offreedom(2-DOF) helicopter systems considering the input constraints and global prescribed ***, radial basis function NN(RBFNN) is employed to estimate the unknown dynamics of the helicopter system. Second, a smooth nonaffine function is exploited to approximate and address nonlinear constraint functions. Subsequently, a new prescribed function is proposed, and an original constrained error is transformed into an equivalent unconstrained error using the error transformation and barrier function transformation methods. The analysis of the established Lyapunov function proves that the controlled system is globally uniformly bounded. Finally, the simulation and experimental results on a constructed Quanser's test platform verify the rationality and feasibility of the proposed control.

关键词： adaptive NN control 2-DOF helicopter global prescribed performance input constraints

Boosting Adaptive Weighted Broad Learning System for Multi-Label Learning

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IEEE/cAA Journal of Automatica Sinica 2024年第11期11卷 2204-2219页

作者： Yuanxin Lin Zhiwen Yu Kaixiang Yang Ziwei Fan c.L.Philip chen the School of computer Science and Engineering in South china University of Technology IEEE the Pengcheng Laboratory

Multi-label classification is a challenging problem that has attracted significant attention from researchers, particularly in the domain of image and text attribute annotation. However, multi-label datasets are prone to serious intra-class and inter-class imbalance problems, which can significantly degrade the classification performance. To address the above issues, we propose the multi-label weighted broad learning system(MLW-BLS) from the perspective of label imbalance weighting and label correlation mining. Further, we propose the multi-label adaptive weighted broad learning system(MLAW-BLS) to adaptively adjust the specific weights and values of labels of MLW-BLS and construct an efficient imbalanced classifier set. Extensive experiments are conducted on various datasets to evaluate the effectiveness of the proposed model, and the results demonstrate its superiority over other advanced approaches.

关键词： Broad learning system label correlation mining label imbalance weighting multi-label imbalance

SOLVING SEcOND ORDER DIFFERENTIAL EQUATIONS IN QUANTUM MEcHANIcS BYORDER REDUcTION

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Acta Mathematica Scientia 2003年第2期23卷 274-288页

作者： c.Ted chen Grace Semiconductor Manufacturing corporation 2nd Floor

Solving the famous Hermite, Legendre, Laguerre and chebyshev equations requires different techniques of unique character for each equation. By reducing these differential equations of second order to a common solvable differential equation of first order, a simple common solution is provided to cover all the existing standard solutions of these named equations. It is easier than the method of generating functions and more powerful than the Probenius method of power series.

关键词： Second order differential equations quantum mechanics common solution

Enhancement of Sinter Densification of SrO-BaO-Nb_2O_5-SiO_2 Tungsten-Bronze Glass-ceramics by Doping with P_2O_5

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Journal of Materials Science & Technology 2013年第8期29卷 731-736页

作者： J.c.chen Y.Zhang Shenyang Research and Development centre for Advanced Materials Institute of Metal ResearchChinese Academy of Sciences State Key Laboratory of New ceramics and Fine Processing Institute of Nuclear and New Energy TechnologyTsinghua University

Densification behaviors of SrO-BaO-Nb2O5-SiO2 based glass-ceramics prepared by conventional sintering were investigated with an emphasis on the influence of P2O5 content. Although P2O5 dopant did not modify the surface crystallization mechanism, it resulted in a decrease of the glass transition temperature, which facilitates the viscous glass flow necessary for sintering. However, premature crystallization of （Sr, Ba）Nb2O6 induced by addition of excess amount of P2O5 essentially retarded sintering due to the formation of closed pores in the matrix. The SrO-BaO-Nb2O5-SiO2 glass with 1.0 mol% P2O5 （SBN-1P） showed the best sinter densification, which was accomplished at about 850 ℃.

关键词： Sintering densification DieLectric properties Glass-ceramic

Vitamin D for the prevention and treatment of pancreatic cancer

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World Journal of Gastroenterology 2009年第27期15卷 3349-3354页

作者： Kun-chun chiang Tai c chen Department of Surgery Chang Gung Memorial Hospital Chang Gung University Taoyuan 333Taiwan China Boston University School of Medicine 715 Albany Street Boston MA 02118 United States

Pancreatic cancer is ranked fi fth among cancer-related deaths worldwide with a 5-year survival rate of less than 5%. currently, surgery is the only effective therapy. However, most patients are diagnosed in the late stage and are not suitable for receiving curative surgery. Moreover, pancreatic cancer doesn't respond well to traditional chemotherapy and radiotherapy, leaving little effective treatment for advanced pancreatic cancer cases. 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], the biologically active form of vitamin D3, was originally identifi ed during studies of calcium and bone metabolism, though it is now recognized that it exerts biological effects in almost every tissue in the body. Abundant evidence has shown that 1α,25(OH)2D3 has antiproliferative, apoptotic, pro-differentiation and antiangiogensis effects in many types of cancer cells in vivo and in vitro, including breast, prostate, and colon. Similarly, the antitumor growth effect of 1α,25(OH)2D3 on pancreatic cells has been demonstrated. The clinical use of 1α,25(OH)2D3 is impeded by the lethal side effects of hypercalcemia and hypercalciuria. Therefore, 1α,25(OH)2D3 analogs, which are either equipotent or more potent than 1α,25(OH)2D3 in inhibiting tumor cell growth but with fewer hypercalcemic and hypercalciuric side effects, have been developed for the treatment of different cancers. Recently, a pre-clinical study demonstrated that a less calcemic analog of 1α,25(OH)2D3, 19-nor-1α,25(OH)2D2 (Paricalcitol), is effective in inhibiting tumor growth in vitro and in vivo , via upregulation of p21 and p27 tumor suppressor genes. Studies on the anti-tumor effects of a more potent analog of Paricalcitol are underway.1α,25(OH)2D3 and its analogs are potentially attractive novel therapies for pancreatic cancer.

关键词： Vitamin D Pancreatic cancer calcitriol Paricalcitol chemoprevention Adenocarcinoma cYP27b1

The Method of Fundamental Solutions for Solving Exterior Axisymmetric Helmholtz Problems with High Wave-Number

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Advances in Applied Mathematics and Mechanics 2013年第4期5卷 477-493页

作者： Wen chen Ji Lin c.S.chen college of Engineering Mechanics Hohai UniversityNanjing 210098JiangsuChina Department of Mathematics University of Southern MississippiHattiesburgMS 39406USA

In this paper,we investigate the method of fundamental solutions(MFS)for solving exterior Helmholtz problems with high wave-number in axisymmetric *** the coefficientmatrix in the linear system resulting fromtheMFS approximation has a block circulant structure,it can be solved by the matrix decomposition algorithm and fast Fourier transform for the fast computation of large-scale problems and meanwhile saving computer memory *** numerical examples are provided to demonstrate its applicability and efficacy in two and three dimensional domains.

关键词： Method of fundamental solutions exterior Helmholtz problem circulant matrix fast Fourier transform axisymmetric domain

Integral Barrier Lyapunov function-based adaptive control for switched nonlinear systems

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Science china(Information Sciences) 2020年第3期63卷 212-225页

作者： Lei LIU Yan-Jun LIU Aiqing chen Shaocheng TONG c.L.Philip chen college of Science Liaoning University of Technology computer Science and Engineering South China University of Technology Navigation college Dalian Maritime University

This paper presents an adaptive control method for a class of uncertain strict-feedback switched nonlinear systems. First, we consider the constraint characteristics in the switched nonlinear systems to ensure that all states in switched systems do not violate the constraint ranges. Second, we design the controller based on the backstepping technique, while integral Barrier Lyapunov functions(i BLFs) are adopted to solve the full state constraint problems in each step in order to realize the direct constraints on state ***, we introduce the Lyapunov stability theory to demonstrate that the adaptive controller achieves the desired control goals. Finally, we perform a numerical simulation, which further verifies the significance and feasibility of the presented control scheme.

关键词： adaptive control switched nonlinear systems integral Barrier Lyapunov functions backstepping technique full state constraints

NUMERIcAL SIMULATION OF SUccINONITRITE DENDRITIc GROWTH IN A FORcED FLOW

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Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 444-450页

作者： Z. chen c.L. chen L.M. Hao School of Science Department of Applied Physics Shaanxi Key Laboratory of Condensed Matter Structures and Properties Northwestern Polytechnical University Xi＇an 710072 China School of Science Xi＇an University of Science ＆ Technology Xi＇an 710054 China

Numerical simulation based on phase field method is performed to describe solidification process of pure material in a free or forced flow. The evolution of the interface is showed, and the effects of mesh grid and flow velocity on succinonitrite shape are studied. These results indicate that crystal grows into an equiaxial dendrite in a free flow and into an asymmetrical dendritic in a forced flow. With increasing flow velocity, the upstream dendritic arm tip grows faster and the downstream arm grows slower. However, the evolution of the perpendicular tip has no significant change. In addition, mesh grid has no influence on dendritic growth shape when mesh grid is above 300×300.

关键词： Phase field method Forced flow Dendritic Succinonitrite Tip velocity