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Simultaneous Stabilization of Port-Hamiltonian Systems Subject to Actuation Saturation and Input Delay

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International Journal of Automation and computing 2021年第5期18卷 849-854页

作者： liang-cheng Cai Department of Electrical Engineering Southwest Jiaotong UniversityEmei 614202China

This paper investigates the simultaneous stabilization of Port-Hamiltonian(PH) systems subject to actuation saturation(AS) and input delay. Firstly, two parallel connecting PH systems subject to the AS and input delay are proposed. Secondly, a simultaneous stabilization control law is designed by a difference between the two feedback control laws containing the input ***, computing a Lyapunov-Krasovskii function assures the simultaneous stabilization of the above systems. Finally, simulation is given to show the correctness of the proposed contents.

关键词： Port-Hamiltonian system(PH) simultaneous stabilization actuator saturation input delay Lyapunov-Krasovskii function

ITERATIVE METHODS FOR THE FORWARD-BACKWARD HEAT EQUATION

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Journal of Computational Mathematics 2005年第4期23卷 419-424页

作者： Xiao-liang cheng Jie Sun Department of Mathematics Zhejiang University Hangzhou 310028 China Department of Mathematics Zhejiang University of Finance and Economics Hangzhou 310012 China

In this paper we propose the finite difference method for the forward-backward heat equation. We use a coarse-mesh second-order central difference scheme at the middle line mesh points and derive the error estimate. Then we discuss the iterative method based on the domain decomposition for our scheme and derive the bounds for the rates of convergence. Finally we present some numerical experiments to support our analysis.

关键词： Forward-backward heat equation Finite difference method Iterative method Coarse mesh

LINEAR FINITE ELEMENT APPROXIMATIONS FOR THE TIMOSHENKO BEAM AND THE SHALLOW ARCH PROBLEMS

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维普期刊数据库

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Journal of Computational Mathematics 2002年第1期20卷 15-22页

作者： Xiao-liang cheng Wei-min Xue Department of Mathematics Zhejiang UniversityXixi CampusHangzhou 310028China Department of Mathematics Hong Kong Baptist UniversityKowloon TongHong Kong

Focuses on a study that discusses the linear finite element approximations for the Timoshenko beam and the shallow arch problems with shear dampening and reduced integration. Information on the Timoshenko beam; Detail... 详细信息

关键词： Timoshenko beam shallow arch shear dampening reduced integration

Iterative methods for a forward-backward heat equation in two-dimension

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Applied Mathematics(A Journal of Chinese Universities) 2010年第1期25卷 101-111页

作者： SUN Jie cheng Xiao-liang School of Mathematics and Statistics Zhejiang University of Finance and Economics Hangzhou310018 China Department of Mathematics Zhejiang University Hangzhou 310027 China

A finite difference method is introduced to solve the forward-backward heat equation in two space dimensions. In this procedure, the backward and forward difference scheme in two subdomains and a coarse-mesh second-order central difference scheme at the middle interface are used. Maximum norm error estimate for the procedure is derived. Then an iterative method based on domain decomposition is presented for the numerical scheme and the convergence of the given method is established. Then numerical experiments are presented to support the theoretical analysis.

关键词： Forward-backward heat equation coarse mesh iterative method.

Development of Modified 304 Stainless Steel Resistant to Stress Corrosion Cracking in Chloride Environment

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Journal of Iron and Steel Research International 2002年第2期9卷 39-44页

作者： liang cheng-hao SHIGEO Tsujikawa Dalian University of Technology The University of Tokyo

The influence of water pollution and welding defects on MIC (microbiologically influenced corrosion) was studied. The open circuit potential (OCP) was measured during MIC test. It was found that OCP shifted to a higher level when the system was inoculated with bacteria while the OCP of those samples in water without bacteria was kept at a low level. The OCP decreased dramatically when MIC started in polluted water. Combination of weld defect heat tint, polluted water and adding bacteria causes MIC happen at high rate. Some elements inside the tubercle were analyzed with EDXA. The pits and biofilm were observed with SEM. Microbiological analysis revealed the difference of bacteria between corroded and uncorroded samples.

关键词： stainless steel microbiologically influenced corrosion open circuit potential shift weld

Advancing electrochemical drilling process via coupling of flow field and electric field in pulsating state generated by a novel tube tool

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Chinese Journal of Aeronautics 2024年第4期37卷 542-555页

作者： liang cheng Xiaolei CHEN Zhisen YE Yongjun ZHANG State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of Advanced Manufacturing Technology of Marine Energy Equipment Guangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Nontraditional Machining and Equipment Guangdong University of TechnologyGuangzhou 510006China

This paper introduces an improvement to electrochemical drilling process by coupling flow field and electric field in pulsating state. A novel tube with half-wedged shape at the end(HW-tube) is prepared, with both sidewall and wedged part of the HW-tube insulated. Only the flat part is utilized to provide electric field for electrochemical drilling. By rotating the HW-tube, both flow field and electric field in pulsating state are generated, alternating in different positions within the inter-electrode gap(IEG). The pulsating flow field enhances the mass transfer process, while pulsating electric field disperses material dissolution process and distribution of electrolytic byproducts. Both pulsating fields are coupled at the same frequency, further enhancing the electrochemical drilling process. Simulation results indicate that both flow field and electric field in pulsating state are generated. Compared to the traditional tube, the HW-tube significantly reduces the number of residual particles in IEG, and this number is further reduced by increasing the rotation speed. Experimental results reveal that the surface quality and dimensional uniformity of small hole are improved with HW-tube. With feed rate of 2.22 mm/min, a small hole with diameter of 1.52± 0.017 mm is drilled, resulting in a surface roughness of 0.331 μm.

关键词： Small holes Electrochemical drilling Tools Pulsating flow field Pulsating electric field

Prediction of Pitting Corrosion Mass Loss for 304 Stainless Steel by Image Processing and BP Neural Network

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Journal of Iron and Steel Research International 2005年第6期12卷 59-62页

作者： ZHANG Wei liang cheng-hao State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 116012 China

Image processing technique was employed to analyze pitting corrosion morphologies of 304 stainless steel exposed to FeCl3 environments. BP neural network models were developed for the prediction of pitting corrosion mass loss using the obtained data of the total and the average pit areas which were extracted from pitting binary image. The results showed that the predicted results obtained by the 2-5-1 type BP neural network model are in good agreement with the experimental data of pitting corrosion mass loss. The maximum relative error of prediction is 6.78%.

关键词： BP neural network image processing pitting corrosion mass loss prediction

Effect of Sulfate Reduced Bacterium on Corrosion Behavior of 10CrMoAl Steel

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Journal of Iron and Steel Research International 2007年第1期14卷 74-78页

作者： WANG Hua liang cheng-hao School of Chemical Engineering Dalian University of Technology Dalian 116012 Liaoning China Eleetromeehanics and Materials Engineering College Dalian Maritime University Dalian 116026 Liaoning China

The effects of sulfate reduced bacterium （SRB） on the corrosion behavior of 10CrMoAl steel in seawater were studied by chemical immersion, potentiodynamic polarization, electrochemical impedance spectroscopy measurement, and scanning electron microscope techniques. The results show that the content of element sulfur in the corrosion product of 10CrMoAl steel in seawater with SRB is up to 9. 23 %, which is higher than that of the same in sterile seawater. X-ray diffraction demonstrates that the main corrosion product is FeS. SRB increases the corrosion rate by anodic depolarization of the metabolized sulfide product. SEM observation indicates that the corrosion product is not distributed continuously; in addition, bacilliform sulfate-reduced bacterium accumulates on the local surface of 10CrMoAl steel. Hence, SRB enhances sensitivity to the localized corrosion of 10CrMoAl steel in seawater.

关键词： sulfate reduced bacterium 10CrMoAl steel localized corrosion

A modified Tikhonov regularization method for a Cauchy problem of a time fractional diffusion equation

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Applied Mathematics(A Journal of Chinese Universities) 2019年第3期34卷 284-308页

作者： cheng Xiao-liang YUAN Le-le liang Ke-wei School of Mathematical Sciences Zhejiang University

In this paper,we consider a Cauchy problem of the time fractional diffusion equation(TFDE)in x∈[0,L].This problem is ubiquitous in science and engineering *** illposedness of the Cauchy problem is explained by its solution in frequency ***,the problem is formulated into a minimization problem with a modified Tikhonov regularization *** gradient of the regularization functional based on an adjoint problem is deduced and the standard conjugate gradient method is presented for solving the minimization *** error estimates for the regularized solutions are obtained under Hp norm priori bound ***,numerical examples illustrate the effectiveness of the proposed method.

关键词： Cauchy problem time-fractional diffusion equation a modified Tikhonov regularization method conjugate gradient method error estimates