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An improved robust and efficient level set algorithm for image segmentation

ICIC Express Letters 2013年第9期7卷 2645-2651页

作者： Liu, Haiying Wang, Binpeng School of Electrical Engineering and Automation China Key Laboratory of Advanced Manufacturing and Measurement and Control Technology Qilu University of Technology Daxue Road Western University Science Park Jinan 250353 China

An improved robust and efficient level set method is proposed with three contributions. In view of avoiding drawbacks of current traditional level set approaches, such as the re-initialization time-consuming procedure and high sensitivities to the noise and blur effect, we in this paper present three strategies that may be taken as our contributions. Three scenarios are considered, namely, the distance regularization term which is defined by double-well potential function by combination with a Tikhonov like regularization term which can guarantee smoothness for the evolution curve. Second, keeping the fitting energy term in the traditional Chan-Vese (C-V) model to weaken the high sensitivities for serious degraded images. Third, the novel edge detector can accurately detect the weak boundaries by rectifying two different parameters to offer suitable convergence and satisfy different necessaries. Experimental studies are presented to verify our improved model via evaluating and comparing with existing algorithms. © 2013 ICIC International.

关键词： Image segmentation

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Hybrid CFD/FEM-BEM simulation of cabin aerodynamic noise for vehicles traveling at high speed

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Science China(Technological Sciences) 2013年第7期56卷 1697-1708页

作者： WANG YiPing ZHEN Xin WU Jing GU ZhengQi XIAO ZhenYi YANG Xue Hubei Key Laboratory of Advanced Technology of Automotive Components Wuhan University of Technology State Key Laboratory of Automotive Simulation and Control Jilin University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Wuhan Ordnance Noncommissioned officers School

Flow passing a vehicle may lead to the increase of the cabin interior noise level through a variety of mechanisms. These mechanisms include vibrations caused by aerodynamic excitations and reradiation from the glass panels, exterior noise trans-mitted and leaked through door seals including gaps and glass edge, and transmission of airborne noise generated by the interaction of flow with body panels. It is of vital importance to predict both the flow fields and the acoustic sources around the ve-hicle to accurately assess the impact of wind induced noise inside the cabin. In the present study, an unstructured segregated finite volume model was used to calculate the flow fields in which a hexahedron grid is used to simplify the vehicle geometry.A large eddy simulation coupled with a wall function model was applied to predict the exterior transient flow fields. The mean flow quantities were thus calculated along the symmetry plane and the vehicle's side windows. A coupled FEM/BEM method was used to compute the vehicle's interior noise level. The total contribution of the interior noise level due to the body panels of the vehicle was subsequently analyzed.

关键词： aerodynamic noise computational fluid dynamics large eddy simulation finite element method boundary element method

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Single-row laser beam with energy strengthened ends for continuous scanning laser surface hardening of large metal components

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Science China(Physics,Mechanics & Astronomy) 2013年第6期56卷 1074-1078页

作者： LI ShaoXia YU Gang ZHANG JingChuan TAN QiaoFeng XU NingHan SUN PeiPei ZHENG CaiYun State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua University Key Laboratory of Mechanics in Advanced Manufacturing Institute of MechanicsChinese Academy of Sciences Beijing Institute of Spacecraft Environment Engineering

For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive *** obtain a uniform hardened band distribution and improve the wear resistance of the sample surface,the binary grating is designed to produce single-row laser beam with energy strengthened at the two *** profile of the laser beam spot was designed to be strip with high length-width ratio to improve the machining efficiency of the hardening of large surfaces.A new advantage is suggested to obtain proportional intensity spots with *** design results show that the diffractive efficiency of the binary grating is more than 70%,and the uniformity is less than 3%.The surface profile of the grating fabricated was measured,which shows that the fabrication error is less than 2%.The application of the binary grating in the laser surface hardening of metal components with large superficies is experimentally investigated,and the results show that the hardness distribution of the modified layer is more uniform than that hardened by Gaussian laser beam or array spots with equal intensity distribution.

关键词： binary grating beam shaping laser surface hardening diffraction

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Stochastic bounded consensus tracking of leader-follower multi-agent systems with measurement noises based on sampled data with general sampling delay

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Chinese Physics B 2013年第12期22卷 555-562页

作者：吴治海彭力谢林柏闻继伟 Key Laboratory for Advanced Process Control of Light Industry of the Ministry of Education School of Internet of Things Engineering Jiangnan University State Key Laboratory for Digital Manufacturing Equipment and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology (HUST)

In this paper we provide a unified framework for consensus tracking of leader-follower multi-agent systems with measurement noises based on sampled data with a general sampling delay. First, a stochastic bounded consensus tracking protocol based on sampled data with a general sampling delay is presented by employing the delay decomposition technique. Then, necessary and sufficient conditions are derived for guaranteeing leader-follower multi-agent systems with measurement noises and a time-varying reference state to achieve mean square bounded consensus tracking. The obtained results cover no sampling delay, a small sampling delay and a large sampling delay as three special cases. Last, simulations are provided to demonstrate the effectiveness of the theoretical results.

关键词： leader-follower multi-agent systems stochastic bounded consensus tracking measurement noises general sampling delay

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Studies on the scattering problem of circular cavity in circular area to in-plane wave

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Journal of Applied Sciences 2013年第22期13卷 5240-5244页

作者： Shi, Wen Pu Wei, Juan School of Mechatronics and Automobile Engineering Yantai University 264005 Yantai China Key Laboratory of Advanced Manufacturing and Control Technology in Universities of Shandong Yantai University China

The wave function expansion method, complex function method and the special function transformation technology were employed to investigate the elastic wave scattering problems of the circular cavity in the circular area under the action of the in-plane disturbance locating on the outer boundary of the circular area. The boundary of the circular area and the boundary of the inner circular cavity produce scattering waves, the superposition principle was used to give the total displacement potentials in the circular area, the boundary stress conditions and the Fourier series expansion were utilized to obtain the infinite algebraic equation group of the unknown coefficients, solve the equations and obtain the unknown coefficients, the variations and distributions of the dynamic tangential stress concentration coefficient on the circular cavity boundary about the dimensionless wave number were discussed and the numerical computation results of the example was given to illustrate the theoretical conclusions. © 2013 Asian Network for Scientific Information.

关键词： Stress concentration

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Computational investigation of the multiphase flow behavior in ironmaking blast furnace

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2nd International Conference on Energy, Environment and Sustainable Development, EESD 2012

作者： Shi, Yanbin Zhang, Lili Fu, Zhenling School of Mechanical and Automotive Engineering Shandong Polytechnic University Jinan China Key Laboratory of Advanced Manufacturing and Measurement and Control Technology for Light Industry in Universities of Shandong Jinan China

ISBN: (纸本)9783037855522

For studying the microscopic mechanism of pulverized coal injection (PCI) process to optimize BF operation further, the multiphase-coupled interactions and combustion phenomena is described by mathematical equations. Some assumptions are employed properly in simulation for solving the equations well. Some physical properties of per-phase obtained through simulating the typical flow behaviors in iron-making process were contrastive analyzed with the field data. The investigation shows that the complex phenomena in a BF can be presented by the computational approach which is proved virtual and robust. The computational results have shown that the gas-solid-powder flow varies spatially, particularly in the raceway;the powder flow is strongly affected by the air and coke particles under the cohesive zone, and by the ore particles upon the cohesive zone;the ability of BF could be enhanced with higher rate of coal injection to a certain extent. © (2013) Trans Tech Publications, Switzerland.

关键词： Blast furnaces

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Rigid rotor dynamic balancing with the influence coefficient method

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Sensors and Transducers 2013年第10期157卷 317-324页

作者： Xu, Xiang Fan, Ping Ping The State Key Laboratory of Fluid Power transmission and Control Zhejiang Provincial Key Laboratory of Advanced Manufacturing Technology Institute of Manufacturing Engineering Zhejiang University Hangzhou 310027 China Mechanical Engineering Department School of Engineering and Science Stevens Institute of Technology Castle Point on Hudson Hoboken NJ 07030-5991 United States

On the base of the causes of the rotor's unbalanced vibration, the rigid rotor mathematic model was established to analyze the vibration form of a rigid rotor under unbalance inertia force. The principle of the influence coefficient method had been presented, and the principle of the cross-correlation method to extract the fundamental frequency signal of unbalance vibration was introduced. The process of conducting 1-plane and 2- plane dynamic balancing were described in detail. The method was found to be effective and practical. Finally through examples testify, it verified the feasibility of the rigid rotor dynamic balancing with the influence coefficient method. © 2013 IFSA.

关键词： Vibration analysis

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Research of paper surface defects detection system based on blob algorithm

Research of paper surface defects detection system based on ...

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International Conference on Information and Automation (ICIA)

作者： Xingguang Qi Xiaoting Li Hailun Zhang Key Laboratory of Advanced Manufacturing and Measurement & Control Technology for Light Industry in Universities of Shandong Qilu University of Technology Jinan China

ISBN: (纸本)9781479913329;9781479940998

Effective recognition and localization of paper defect based on machine vision is the key issue for paper defect detection system. This paper proposed an improved algorithm by combination with Blob analysis algorithm and image preprocessing approach to detect the paper defects which exist in captured images by a linear charge coupled device (CCD) camera. First, the defected images are preprocessed, such as image denoising, image segmentation, connectivity analysis, and then extract effective paper textures: defect amount, regional area, long axis, short axis, central position and so on, meanwhile draw the minimum bounding rectangles. Compared with the traditional morphology algorithm and threshold segmentation and fractal feature algorithm, the improved algorithm is validated by a great deal of experimental results with high detection efficiency and defects localization accuracy.

关键词： Algorithm design and analysis Image segmentation Feature extraction Image denoising Instruments Educational institutions Paper making

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Study on the effect of tool geometrical parameters on cutting forces based on finite element method

Study on the effect of tool geometrical parameters on cuttin...

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2012 International Conference of Health, Structure, Material and Environment, HSME 2012

作者： Zhitao, Tang Tao, Yu Liqiang, Xu School of Mechanical and Electrical Engineering and Automobile Engineering Yantai University Yantai 264005 China Key Laboratory of Advanced Manufacturing and Control Technology Universities of Shandong Yantai 264005 China

ISBN: (纸本)9783037856000

Based on finite element software DEFORM-3D, a three-dimensional oblique cutting model for aerospace aluminum alloy was built. The material's flow stress behavior was described with Johnson-Cook constitutive equation. The separation of the chips with the workpiece was realized by the combination of adaptive remeshing technique and separation criterion. The material's failure was defined by adopting Cockcroft & Latham fracture criterion. The tool-chip friction model was the combination of a Coulomb friction model and shear (sticking) friction model. To validate the finite element model, cutting tests were conducted. The effects of tool geometrical parameters such as flank wear, cutting edge inclination and corner radius on cutting forces were analyzed by three-dimensional oblique finite element model. © (2013) Trans Tech Publications, Switzerland.

关键词： Finite element method

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Motion analyses of D-type driving mechanism

Motion analyses of D-type driving mechanism

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4th International Conference on manufacturing Science and technology, ICMST 2013

作者： Li, Shi Yi Shi, Wen Pu Department of mechanical and electrical engineering Yantai Automobile Engineering Professional College 265500 China Key Laboratory of Advanced Manufacturing and Control Technology in Universities of Shandong Yantai University 264005 China

ISBN: (纸本)9783037858677

Geometric analyses and mechanical analytical method are used to study a kind of D-type driving mechanism. The theoretical formulae of computing angular velocities of the connecting rod and the rocker are given, and the linear velocity of the driving point C is obtained, and the finite differential numerical method for computing the angular velocities of the connecting rod and the rocker is also introduced. The results of the given numerical example show the feasibility of the theoretical conclusions here. © (2013) Trans Tech Publications, Switzerland.

关键词： Motion analysis

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