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NUMERICAL SIMULATION OF TWO-DIMENSIONAL DAM-BREAK FLOWS IN CURVED CHANNELS

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Journal of Hydrodynamics 2007年第6期19卷 726-735页

作者： BAI Yu-chuan XU Dong LU Dong-qiang Institute for Sediment on River and Coast 300072 China shanghai Institute of Applied Mathematics engineering School of Civil Engineering Tianjin University Tianjin and Mechanics Shanghai University Shanghai 200072 China

Two-dimensional transient dam-break flows in a river with bends were theoretically studied. The river was modeled as a curved channel with a constant width and a flat bottom. The water was assumed to be an incompressible and homogeneous fluid. A channel-fitted orthogonal curvilinear coordinate system was established and the corresponding two-dimensional shallow-water equations were derived for this system. The governing equations with well-posed initial and boundary conditions were numerically solved in a rectangular domain by use of the Godunov-type finite-difference scheme, which can capture the hydraulic jump of dam-break flows. The comparison between the obtained numerical results and the experimental data of Miller and Chaudry in a semicircle channel shows the validity of the present numerical scheme. The mathematical model and the numerical method were applied to the dam-break flows in channels with various curvatures. Based on the numerical results, the influence of river curvatures on the dam-break flows was analyzed in details.

关键词： dam-break flow shallow-water equations,channel bend curvilinear coordinate Godunov-type finite-difference scheme

Preparation and Photoconductivity of Fe-Phthalocyanine Derivation and C_(60) Composite Films

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Journal of shanghai university(English Edition) 2001年第2期5卷 156-159页

作者： CHEN Jian ming, ZHANG Jian cheng, SHEN Yue, LIU Xiu hong, YANG Lin hong school of Material science and engineering, shanghai university, shanghai, 200072, china school of Material science and engineering Shanghai University Shanghai China

Fe (III) 2,9,16,23 tertracarboxy phthalocyanine (Fe (III) taPc) was synthesized, and bonded to polystyrene (PS) with covalence by Friedel Crafts reaction to form a new polymer (Fe (III) taPc PS) (polymer (II)). UV VIS and Infrared spectra indicated that Fe (III) taPc was successfully bonded to PS. A photoreceptor device of sandwich structure consisting of alternate layers of polymer (II) and fullerene (C 60 ) was prepared. The experiment results show that the photoconductivity of the photoreceptor is higher than that of the single layer film of polymer (II) or C 60 , because of the charge transfer effect between the layers.

关键词： phthalocyanine polystyrene C 60 photoconductivity composite films

Hybrid method for global optimization using more accuracy interval computation

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Journal of shanghai university(English Edition) 2011年第5期15卷 445-450页

作者：崔中浩雷咏梅 school of computer engineering and science Shanghai University

In this paper, a novel hybrid method is presented for finding global optimization of an objective function. Based on the interval computation, this hybrid method combines interval deterministic method and stochastic evolution method. It can find global optimization quickly while ensuring the deterministic and stability of the algorithm. When using interval computation, extra width constraints accuracy of interval computation results. In this paper, a splitting method to reduce the extra width is introduced. This method is easy and it can get a more precise interval computation result. When finding the global optimization, it can increase the efficiency of pruning. Several experiments are given to illustrate the advantage of the new hybrid method.

关键词： interval arithmetic global optimization interval computation extra width hybrid method

A THREE-DIMENSIONAL DESINGULARIZED HIGH ORDER PANEL METHOD BASED ON NURBS

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Journal of Hydrodynamics 2008年第2期20卷 137-146页

作者： GAO Zhi-liang ZOU Zao-jian State Key Laboratory of Ocean engineering Shanghai Jiaotong University Shanghai 200030 China school of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030 China

A desingularized high order panel method based on Non-Uniform Rational B-Spline （NURBS） was developed to deal with three-dimensional potential flow problems. A NURBS surface was used to precisely represent the body geometry. Velocity potential on the body surface was described by the B-spline after the source density distribution on the body surface had been solved. The collocation approach was employed to satisfy the Neurnann boundary condition and Gaussian quadrature points were chosen as both the collocation points and the source points. The singularity was removed by a combined method, so the process of the numerical computation was non-singular. In order to verify the method proposed, the unbounded flow problems of sphere and ellipsoid, the wave-making problem of a submerged ellipsoid were chosen as computational examples. It is shown that the numerical results are in good agreement with analytical solutions and other numerical results in all cases, and sufficient accuracy of numerical solution can be reached with a small number of panels.

关键词： potential flow high order panel method Non-Uniform Rational B-Spline (NURBS) desingularization

A LINEAR HYBRID MODEL OF MSE AND BEM FOR FLOATING STRUCTURES IN COASTAL ZONES

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Journal of Hydrodynamics 2006年第6期18卷 649-658页

作者： ZHANG Jun MIAO Guo-ping school of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030China The First Engineers Scientific Research Institute of the General Armaments Wuxi 214035 China

A linear hybrid model of Mild Slope Equation （MSE） and Boundary Element Method （BEM） is developed to study the wave propagation around floating structures in coastal zones. Both the wave refraction under the influence of topography and the wave diffraction by floating structures are considered. Hence, the model provides wave properties around the coastal floating structures of arbitrary shape but also the wave forces on and the hydrodynamic characteristics of the structures. Different approaches are compared to demonstrate the validity of the present hybrid model. Several numerical tests are carried out for the cases of pontoons under different circumstances. The results show that the influence of topography on the hydrodynamic characteristics of floating structures in coastal regions is important and must not be ignored in the most wave period range with practical interests.

关键词： hybrid model Mild Slope Equation (MSE),Boundary Element Method (BEM) marine floating structures,coastal regions wave propagation wave force

IDENTIFICATION OF ABKOWITZ MODEL FOR SHIP MANOEUVRING MOTION USING ε-SUPPORT VECTOR REGRESSION

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Journal of Hydrodynamics 2011年第3期23卷 353-360页

作者： ZHANG Xin-guang ZOU Zao-jian school of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China school of Naval Architecture Ocean and Civil Engineering and State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200240 China

By analyzing the data of longitudinal speed, transverse speed and rudder angle etc. in the simulated 10°/10°zigzag test, the hydrodynamic derivatives in the Abkowitz model for ship manoeuvring motion are identified by using e-Support Vector Regression （ε -SVR）. To damp the extent of parameter drift, a series of random numbers are added into the training samples to reconstruct the training samples. The identification results of the hydrodynamic derivatives are compared with the Planar Motion Mechanism （PMM） test results to verify the identification method. By using the identified Abkowitz model, 20°/20° zigzag test is numerically simulated. The simulated results are compared with those obtained by using the Abkowitz model where the hydrodynamic derivatives are obtained from PMM tests. The agreement is satisfactory, which shows that the regressive Abkowitz model has a good generalization performance.

关键词： ship manoeuvring Abkowitz model parameter identification e -Support Vector Regression ( ~ -SVR)

Research on Vibration Properties of the Drill-punch Mechanism for Taphole Drill

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Journal of university of science and Technology Beijing 2001年第4期8卷 311-313页

作者： Jianping Liu, Yongfang Liao 1) Mechanical engineering school, university of science and Technology Beijing. Beijing 100083, china 2) shanghai Baoshan Iron & Steel Corporation. shanghai 201914, china Mechanical engineering school University of Science and Technology Beijing Beijing 100083 China shanghai Baoshan Iron and Steel Corporation Shanghai 201914 China

A new type taphole drill was designed. The vibration properties of them drill-punch mechanism for the new type taphole drill were researched, the laws of its inherent characteristics were found. The measures to add punch amplitude and to reduce traverse vibration were put forward. The result showed that decreasing the frequency of vibration motors or increasing the stiffness of springs, and increasing excitation force can improve the vibration properties of the properties of the drill-punch mechanism.

关键词： taphole drill equipment in the cast house vibrating machinery

Variable structure multiple model for articulated human motion tracking from monocular video sequences

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science china(Information sciences) 2012年第5期55卷 1138-1150页

作者： HAN Hong 1,TONG MingLei 2,CHEN ZhiChao 1 & FAN YouJian 1 1 Key Laboratory of Intelligent Perception and Image Understanding of Ministry of Education of china,Institute of Intelligent Information Processing,Xidian university,Xi'an 710071,china 2 school of computer and Information engineering,shanghai university of Electric Power,shanghai 200090,china Key Laboratory of Intelligent Perception and Image Understanding of Ministry of Education of china Institute of Intelligent Information Processing Xidian University Xi’an China school of computer and Information engineering Shanghai University of Electric Power Shanghai China

A new model-based human body tracking framework with learning-based theory is introduced in this *** propose a variable structure multiple model (VSMM) framework to address challenging problems such as uncertainty of motion styles,imprecise detection of feature points,and ambiguity of joint *** human joint points are detected automatically and the undetected points are estimated with Kalman *** motion models are learned from motion capture data using a ridge regression *** model set that covers the total motion set is designed on the basis of topological and compatibility relationships,while the VSMM algorithm is used to estimate quaternion vectors of joint *** using real image sequences and simulation videos demonstrate the high efficiency of our proposed human tracking framework.

关键词： human motion tracking ridge regression model groups design variable structure multiple model (VSMM) motion model group adaptation

NUMERICAL SIMULATION OF TRANSIENT FLOW AROUND A SHIP IN UNSTEADY BERTHING MOTION

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Journal of Hydrodynamics 2009年第3期21卷 379-385页

作者： WANG Hua-ming ZOU Zao-jian TIAN Xi-min school of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China school of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China Marine Design and Research Institute of china Shanghai 200011 China

Ship berthing is a specific maneuver operation. The flow around a berthing ship and the forces acting on the hull are quite different from those for a ship in normal navigation. By solving the unsteady Reynolds-Averaged Navier-Stokes （RANS） equations, the transient flow field around a ship undergoing unsteady lateral motion is simulated and the varying lateral hydrodynamic force acting on the hull is evaluated in this article. The numerical results obtained with different turbulence models are analyzed and compared with experimental results and other numerical results published in literature, and a turbulence model more suitable for simulation of the viscous flow around a ship undergoing unsteady berthing is determined.

关键词： ship berthing transient flow lateral hydrodynamic force numerical simulation