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A generalized mean shift tracking algorithm

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Science china(Information sciences) 2011年第11期54卷 2373-2385页

作者： CHEN JianJun 1,4,ZHANG SuoFei 1,AN GuoCheng 2.& WU ZhenYang 1,31 School of Information Science and Engineering,Southeast university,Nanjing 2.0096,china 2.Intelligence Engineering {2.,Institute of Software Chinese Academy of sciences,beijing 100190,china 3 Key {2.oratory of Underwater Acoustic Signal Processing of Ministry of Education,Southeast university,Nanjing 2.0096,china 4 Nanjing Research Institute of Electronic Technology,Nanjing 2.0013.china School of Information Science and Engineering Southeast University Nanjing China Nanjing Research Institute of Electronic Technology Nanjing China Intelligence Engineering lab Institute of Software Chinese Academy of Sciences Beijing China Key laboratory of Underwater Acoustic Signal Processing of Ministry of Education Southeast University Nanjing China

CAMSHIFT algorithm and Comaniciu/Meer algorithm are two fundamental frameworks of mean shift procedure for video target *** paper generalizes the two well-known mean shift tracking algorithms,originally due to Bradski and Comaniciu/Meer.A new general similarity function which defines the distance between the target model and target candidate is employed to calculate the pixel weights and the target *** target size is iteratively estimated and updated based on the zeroth order moment of the pixel *** we prove that both the CAMSHIFT algorithm and the Comaniciu/Meer algorithm can be included in the generalized mean shift tracking *** tracking performances of three mean shift algorithms in the unified framework are shown and compared in the experimental results.

关键词： mean shift CAMSHIFT video target tracking similarity measure

Leakproof secret sharing protocols with applications to group identification scheme

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Science china(Information sciences) 2012年第5期55卷 1172-1185页

作者： TANG ChunMing 1,2.& GAO ShuHong 3 1 School of Mathematics and Information Science,Guangzhou university,Guangzhou 510006,china 2.State Key {2.oratory of Information Security,Institute of Software Science,Chinese Academy of sciences,beijing 100049,china 3 Department of Mathematical sciences,Clemson university,SC 2.634,USA School of Mathematics and Information Science Guangzhou University Guangzhou China State Key laboratory of Information Security Institute of Software Science Chinese Academy of Sciences Beijing China Department of Mathematical sciences Clemson University Clemson USA

In a traditional (t,n)-threshold secret sharing scheme,t or more honest participants can reconstruct the secret *** the reconstruction process,the individual shares and the secret key K are revealed,hence K is shared once *** this paper,we firstly give the definition of leakproof secret sharing scheme which is composed of a distribution protocol and a proof protocol,then propose two leakproof secret sharing protocols,a computationally secure protocol and an information-theoretically secure *** our protocols,t or more participants can jointly prove that they hold the secret K by using a multi-prover zero-knowledge argument of *** a result,the secret K will be shared for as many times as ***,each participant can detect the dealer in the distribution protocol from cheating,and any verifier can prevent non-qualified set of participants in proof protocol from *** an example of the practical impact of our work we use our techniques to construct group identification schemes with zero-knowledge.

关键词： secret sharing leakproof secret sharing multi-prover zero-knowledge argument proof of knowl-edge group identification scheme

Study on the J-Integral and Failure Assessment Line of Electron Beam Welded Thick TC4-DT Alloy Joints

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稀有金属材料与工程 2011年第S4期40卷 58-62页

作者： Lu Wei1,Shi Yaowu1,Li Xiaoyan1,Lei Yongping1,Gong Shuili2.Guan Qiao2.Zhao Haiyan3 1 College of Materials Science and Engineering,beijing university of Technology,beijing 10012.,china2.Science and Technology on Power Beam Processes laboratory,beijing Aeronautical Manufacturing Technology Research Institute,beijing 10012.,china3 Dept of Mechanical Engineering,Tsinghua university,beijing 100084,china beijing Univ Technol Coll Mat Sci & Engn Beijing 100124 Peoples R China beijing Aeronaut Mfg Technol Res Inst Sci & Technol Power Beam Proc Lab Beijing 100124 Peoples R China Tsinghua Univ Dept Mech Engn Beijing 100084 Peoples R China

The effects of strength mis-matching on J-integral and failure assessment line (FAL) of electron beam welded thick TC4-DT titanium alloy joints have been *** and elastic-plastic finite elements (FE) calculations on centre crack tensile (CCT) specimens were made,and the condition of 2.% strength mis-matching was *** results indicate that the limit load of the joint can be substituted by that of the base *** error of substitution is less than 5%.The failure assessment lines for both over-matching and under-matching joints are increasingly close to that of the base metal,with the ratio of weld width to specimen width (H/W) ***,the failure assessment lines of the joints can be devised using the stress-strain curves of the base metal,which will be convenient for the practical application of engineering

关键词： electron beam welding TC4-DT alloy joints limit load J-integral failure assessment line

Numerical Simulation of Multi-track and Multi-layer Temperature Field on Laser Direct Metal Shaping

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武汉理工大学学报 2006年第S3期28卷 1111-1116页

作者： LONG Risheng~(1,2. LIU Weijun~1 (1.Advanced Manufacture lab,Shenyang Institute of Automation,Shenyang 110016,china, 2.Graduate School,Chinese Academy of {2.,beijing 100039,china) Advanced Manufacture lab Shenyang Institute of AutomationShenyang 110016China Advanced Manufacture lab Shenyang Institute of AutomationShenyang 110016China Graduate School Chinese Academy of SciencesBeijing 100039China

To improve the mechanical properties of the parts fabricated by Laser Direct Metal Shaping(LDMS),it is of great significance to understand the distribution regularities of transient temperature field during LDMS *** on the“el- ement birth and death”technique of finite element method,a three-dimensional multi-track and multi-layer model for the transient temperature field analysis of LDMS is developed by ANSYS Parametric Design Language(APDL)for the first *** the fab- ricated modal,X-direction parallel reciprocating scanning paths is *** the same process parameters,the simulation results show good agreement with the microstructure features of samples which fabricated by LDMS.

关键词： laser direct metal shaping transient temperature field numerical simulation

Spark Effect on the Densification of SiCp/Al Composites by SPS

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Journal of Wuhan university of Technology(Materials Science) 2006年第1期21卷 72-75页

作者：顾晓峰 State Key laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

SiCp/ Al composites containing high volume fraction of SiC particles were fabricated by spark plasma sintering （SPS）. and their thermophysical properties, such as thermal conductivity （TC） and *** of thermal expansion （CTE）, were characterized. The electric field in the vacuum column was calculated and the generation condition of the spark was analyzed. Spark can be generated by a low current if the cavity in the green body is large enough. A high relative density of the composites was successfully achieved through the optimization of sintering parameters. The measured TCs of the SiCp/ Al composites fabricated by SPS are higher than 195 W/m ·K.

关键词： spark plasma sintering SiCp/ Al composites thermal conductivity coeffwient of thermal expansion densification

Microstructure and Wear Resistance Evolution of HVOFSprayed WC-(W,Cr)_2.-Ni Coating with Post Heat Treatment In Air Atmosphere

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稀有金属材料与工程 2012年第S1期41卷 388-393页

作者： Hou Guoliang1,2.Zhou Huidi1,An Yulong1,2.Liu Guang1,2.Chen Jianmin1,Chen Jie1,2.1 State Key laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of sciences,Lanzhou 730000,{2. 2.Graduate university,Chinese Academy of sciences,beijing 100049,{2. Chinese Acad Sci Lanzhou Inst Chem Phys State Key Lab Solid Lubricat Lanzhou 730000 Peoples R China Chinese Acad Sci Grad Univ Beijing 100049 Peoples R China

WC-(W,Cr)2.-Ni coating was prepared on 1Cr18Ni9Ti stainless steel and C-2.6 Ni-base Hastelloy by high velocity oxy-fuel(HVOF)*** effect of post heat treatment in air atmosphere on the microstructure,phase composition,microhardness,fracture toughness,and wear resistance of HVOF-sprayed WC-(W,Cr)2.-Ni coating was *** microstructure and phase composition of the coatings were analyzed by means of field emission scanning electron microscopy(FESEM)and X-ray diffraction(XRD).The microhardness and fracture toughness of the coatings were measured using a microhardness tester and a Vickers hardness ***,dry friction and wear behavior of the coatings sliding against Si3N4 ball was investigated using an oscillating friction and wear tester;and the worn surfaces of the coatings were analyzed by means of scanning electron microscopy(SEM).It was found that heat treatment within 500-800°C resulted in crystallization of amorphous phase in as-sprayed coating,generating nanoscale new phases such as NiWO4,CrWO4 and ***,heat treatment led to increase of the microhardness of as-sprayed coating,and the highest microhardness was obtained after heat treatment at 800°*** fracture toughness and wear resistance of the as-sprayed coating increased with increasing heat treatment temperature up to 700°C but tended to decrease with further elevating *** other words,the mechanical properties and wear resistance of the as-sprayed coatings were worsened owing to excessive growth of oxidation grains and depletion of ductile Ni binder after heat treatment above 700°*** it was suggested that as-sprayed ceramic composite coating should be post heat treated in air at a moderate temperature of 700°C so as to achieve the optimized mechanical properties and wear resistance.

关键词： HVOF WC-(W,Cr)2.-Ni coating post heat treatment microstructure wear resistance

Analysis and Control on Fracture of 2.Mn2. High Tensile Steel for Round Link Chain

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Journal of Iron and Steel Research International 2011年第S1期18卷 898-902页

作者： CAO Shu-wei 1,2.KANG Yong-lin 1,3,ZHAO Xian-ping 2.YANG Chang-chun 1 (1.School of Materials Science and Engineering,university of Science and Technology beijing,beijing 100083,china 2.Technology center of Anyang Iron & Steel Group Co.,Ltd.,Anyang 455004,Henan,china 3.State Key laboratory for Advanced Metals and Materials,university of Science and Technology beijing,beijing 100083,china) Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Anyang Iron & Steel Grp Co Ltd Ctr Technol Anyang 455004 Henan Peoples R China Univ Sci & Technol beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China

Based on the phenomenon of brittle fracture occurred during tensile test for 2.Mn2. high strength circular chain used in coal mines,the fracture property is regarded as intercrystalline brittle one after macroscope observation and metallographic *** is analysed that the intercrystalline brittle fracture is due to high tempering temperature and limited processing site where final products are piled together after heat treatment,which lead to a lower cooling rate of internal chain,with Si,Mn and P etc elements segregating and enriching in the austenite grain boundary and forming high tempering *** these circular chains are tempered again for one hour at 670℃,and oil-cooled rapidly,due to the reversibility of high temper brittleness for structural alloy steel,the high temper brittleness can be eliminated and products are completely qualified after tensile inspection.

关键词： high strength circular chain metallographic examination brittle fracture high tempering brittleness improvement measures

Numerical Simulation of Transient Thermal Stress Field for Laser Metal Deposition Shaping

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武汉理工大学学报 2006年第S3期28卷 1025-1030页

作者： LONG Risheng~(1,2. LIU Weijun~1 (1.Advanced Manufacture lab,Shenyang Institute of Automation,Shenyang 110016,china 2.Graduate School,Chinese Academy or {2.,beijing 100039,china) Advanced Manufacture lab Shenyang Institute of AutomationShenyang 110016China Graduate School Chinese Academy of SciencesBeijing 100039China Advanced Manufacture lab Shenyang Institute of AutomationShenyang 110016China

To decrease thermal stress during laser metal deposition shaping(LMDS)process,it is of great importance to learn the transient thermal stress distribution *** on the“element life and death”technique of finite element analy- sis(FEA),a three-dimensional multi-track and multi-layer numerical simulation model for LMDS is developed with ANSYS parametric design language(APDL)for the first time,in which long-edge parallel reciprocating scanning paths is introduced. Through the model,detailed simulations of thermal stress during whole metal cladding process are conducted,the generation and distribution regularities of thermal stress are also discussed in *** the same process parameters,the simulation results show good agreement with the features of samples which fabricated by LMDS.

关键词： LMDS FEA transient thermal stress field numerical simulation

Project research of GIS data based on AutoCAD

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中国有色金属学会会刊：英文版 2005年第S1期15卷 244-246页

作者： YAO Xin ~(1, 2. (1. Institute of Geology and Geophysics, Chinese Academy of sciences, beijing 10002., {2. 2. The Geomatics and Applications laboratory, Liaoning Technical university, Fuxin 12.000, {2.) Chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China Liaoning Tech Univ Geomat & Applicat Lab Fuxing 123000 Peoples R China

The digitalization software developed based on AutoCAD is one important platform of GIS data gather. But because AutoCAD itself is not the software of GIS, it can not be used to collect the attribute data. And conversion data to GIS software often lose some information such as color, line style, symbol shape. By using the XDATA, the Handle, the Group of AutoCAD and the provided ObjectArx to Redevelop, under AutoCAD condition, the attribute information collection with space information were realized, also did the AutoCAD symbol integrity and accurate expresses, then the demand of the digit graphics was satisfied.

关键词： AutoCAD attribute data data transfer ObjectArx XDATA