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An improved approach to the efficient construction of and search operations in motion graphs

science china(Information sciences) 2012年第5期55卷 1042-1051页

作者： GAO Yan 1,CHEN ZhiHua 2,CHEN MinGang 3.& SHEN yang 3.1 Software Engineering Institute,East china Normal university,Shanghai 200062,{3. 2 Department of computer science and Engineering,East china university of science and technology,Shanghai 20023.,{3. 3.Department of computer science and Engineering,Shanghai Jiao Tong university,Shanghai 200240,{3. 1. Software Engineering Institute East China Normal University Shanghai 200062 China2. Department of Computer Science and Engineering East China University of Science and Technology Shanghai 200237 China3. Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

Motion graphs have been widely used as an effective technique in the synthesis of human *** synthesize well-formed motions,motion graphs require smooth transitions and good ***,the time and costs grow quadratically as the graph size *** this paper,we present a method to set up a hierarchical structure,called a structure *** coarse level of this graph models different motion categories and their transitions,and the fine level mainly captures different motion *** interpolation space method is used to improve the graph connectivity at the fine *** structure guides the establishment of a faster and more realistic graphical *** the building process,this structure also helps with searching the motion graph,by performing a traverse search and placing the findings into a direct look-up table or local search ***,when there is no direct link between the different motions,a navigation map is introduced to conduct an appropriate search path via a series of transition motion *** experimental results indicate that our approach could lower the computation time in construction and searching,while simultaneously providing a richer variety of motion styles.

关键词： motion graph structure table registration curve motion interpolation

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Image universal steganalysis based on best wavelet packet decomposition

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science china(Information sciences) 2010年第3期53卷 634-647页

作者： LUO Xiangyang1,2, LIU FenLin1, yang ChunFang1 & WANG DaoShun2 1Information science and {3. Institute, Zhengzhou 450002, china 2Department of computer science and {3., Tsinghua university, beijing 100084, china 1. Information science and technology Institute Zhengzhou 450002 China2. Department of Computer Science and Technology Tsinghua University Beijing 100084 China

Based on the best wavelet packet decomposition of images, a new universal steganalysis method with high detection correct ratio is proposed. First, the best wavelet packet decomposition of image based on the Shannon entropy information cost function is made. Second, high order absolute characteristic function moments of histogram extracted from the coefficient subbands obtained by best wavelet packet decomposition are regarded as features. Finally, these features are processed and a back-propagation (BP) neural network is designed to classify original and stego images. Three different steganalysis algorithms for three different cases of background and application condition are presented. To validate the performance of the proposed method, a series of experiments are made for six kinds of typical steganography methods, i.e. LSB, LTSB, PMK, Jsteg, F5 and JPHide. Results show that, the average detection accuracy of the proposed method exceeds at least 6.4% and up to 15.4% and has a better universal performance than its closest competitors. Furthermore, the proposed method can provide reference for designing the pattern recognition and classification algorithm based on best wavelet packet decomposition.

关键词： steganography digital images universal steganalysis best wavelet packet decomposition BP neural network

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Construction of nonbinary quantum cyclic codes by using graph method

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science in china(Series F) 2005年第6期48卷 693-702页

作者： LIU Tailin1,2,3. wen qiaoyan1 & LIU Zihui4 1. School of science, {3. university of Posts and Telecommunications, {3. 100876, china 2. State Key Laboratory of Integrated Services Network, Xidian university, Xi’an 710071,china 3. Shandong Finance Institute, Jinan 250014, china 4. School of Mathematical sciences, Peking university, {3. 100871, china 1. School of science Beijing University of Posts and Telecommunications 100876 Beijing China 2. State Key Laboratory of Integrated Services Network Xidian University 710071 Xi’an China 3. Shandong Finance Institute 250014 Jinan China 4. School of Mathematical sciences Peking University 100871 Beijing China

Using the graph method proposed by Schlingemann and Werner, this paper introduces a technique to construct nonbinary quantum cyclic codes and provides a specific example. We also construct the quantum codes [[8, 2, 4]... 详细信息

关键词： nonbinary quantum stabilizer codes quantum cyclic codes

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CUDA-Zero:a framework for porting shared memory GPU applications to multi-GPUs

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science china(Information sciences) 2012年第3期55卷 663-676页

作者： CHEN DeHao , CHEN wenGuang & ZHENG WeiMin Department of computer science and {3., Tsinghua university, beijing 100084, china 1. Department of computer science and technology Tsinghua University Beijing 100084 China

As the prevalence of general purpose computations on GPU, shared memory programming models were proposed to ease the pain of GPU programming. However, with the demanding needs of more intensive workloads, it’s desirable to port GPU programs to more scalable distributed memory environment, such as multi-GPUs. To achieve this, programs need to be re-written with mixed programming models (e.g. CUDA and message passing). Programmers not only need to work carefully on workload distribution, but also on scheduling mechanisms to ensure the efficiency of the execution. In this paper, we studied the possibilities of automating the process of parallelization to multi-GPUs. Starting from a GPU program written in shared memory model, our framework analyzes the access patterns of arrays in kernel functions to derive the data partition schemes. To acquire the access pattern, we proposed a 3.tiers approach: static analysis, profile based analysis and user annotation. Experiments show that most access patterns can be derived correctly by the first two tiers, which means that zero efforts are needed to port an existing application to distributed memory environment. We use our framework to parallelize several applications, and show that for certain kinds of applications, CUDA-Zero can achieve efficient parallelization in multi-GPU environment.

关键词： CUDA parallelization data access pattern multi-GPU

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Experimental results and analysis of sparse microwave imaging from spaceborne radar raw data

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science china(Information sciences) 2012年第8期55卷 1801-1815页

作者： JIANG ChengLong1,2,3.ZHANG BingChen1,2,ZHANG Zhe1,2,3.HONG wen1,2&WU YiRong1,2 1S cience and technology on Microwave Imaging Laboratory,beijing 100190,{3. 2I nstitute of Electronics,Chinese Academy of sciences,beijing 100190,{3. 3. raduate university of Chinese Academy of sciences,beijing 100190,{3. 1. science and technology on Microwave Imaging Laboratory Beijing 100190 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China3. Graduate University of Chinese Academy of Sciences Beijing 100190 China

Sparse microwave imaging is a novel radar framework aiming to bring revolutions to the microwave imaging according to the theory of sparse signal *** compressive sensing(CS)is introduced to synthetic aperture radar(SAR)imaging in recent years,the current SAR sparse imaging methods have shown their advantages over the traditional matched filtering ***,the requirement for these methods to process the compressed range data results in the increase of the hardware *** the SAR sparse imaging method that directly uses the raw data is *** paper describes the method of SAR sparse imaging with raw data directly,presents the analysis of the signal-to-noise ratio(SNR)in the echo signal by combining the traditional radar equation with the compressive sensing theory,and provides the tests on 2-D simulated SAR *** simulation results demonstrate the validity of the SNR analysis,and the good performance of the proposed method while a large percentage of the raw data is *** experiment with RadarSat-1 raw data is also carried out to show the feasibility of processing the real SAR data via the method proposed in this *** method is helpful for designing new SAR systems.

关键词： sparse microwave imaging synthetic aperture radar(SAR)imaging compressive sensing signalto-noise ratio raw data

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Synthesis of nano onion-like fullerenes by using Fe/Al_2O_3.as catalyst by chemical vapor deposition

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Chinese science Bulletin 2009年第1期54卷 137-141页

作者： LIU XuGuang1,2,WANG CunJing1,2,yang YongZhen1,3.GUO XingMei1,2,wen HaiRong1,2 & XU BingShe1,3.1 Key Laboratory of Interface science and Engineering in Advanced Materials,Ministry of Education,Taiyuan {3. of Tech-nology,Taiyuan 03.024,china 2 College of Chemistry and Chemical Engineering,Taiyuan {3. of technology,Taiyuan 03.024,china 3.College of Materials science and Engineering,Taiyuan {3. of technology,Taiyuan 03.024,china Key Laboratory of Interface science and Engineering in Advanced Materials Ministry of Education Taiyuan University of Technology Taiyuan 030024 China College of Chemistry and Chemical Engineering Taiyuan University of Technology Taiyuan 030024 China College of Materials science and Engineering Taiyuan University of Technology Taiyuan 030024 China

Nano-carbon materials were synthesized by the catalytic decomposition of acetylene at 400℃ by using Fe/Al2O3.as catalyst. The product was refluxed in 3.% concentrated HCl at 60℃ for 48 h in order to re-move the catalyst support. The samples were examined by scanning and high resolution transmission electron microscopy,energy dispersive spectroscopy and X-ray diffraction. The results show that nano onion-like fullerenes encapsulating a Fe3. core were obtained. These had a structure of stacked graphitic fragments,with diameters ranging from 15―50 nm. When the product was further heat-treated at 1100℃ for 2 h,nano onion-like fullerenes with a clear concentric graphitic layer structure were obtained. The growth mechanism of nano onion-like fullerenes encapsulating metal cores is suggested to follow a vapor-solid growth model.

关键词：纳米碳材料化学蒸发沉积作用合成增长机制

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Experimental measurement of growth patterns on fossil corals:Secular variation in ancient Earth-Sun distances

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Chinese science Bulletin 2010年第35期55卷 4010-4017页

作者： ZHANG WeiJia1,3.4,LI ZhengBin2,3.& LEI yang1 1 Department of Physics,Peking university,beijing 100871,{3. 2 Department of Electrical Engineering and computer science,Peking university,beijing 100871,{3. 3.State Key Laboratory of Advanced Optical Communication Systems & Networks,Peking university,beijing 100871,{3. 4 Committee of Yuanpei Honors Program,Peking university,beijing 100871,{3. Department of Physics Peking University Beijing 100871 China State Key Laboratory of Advanced Optical Communication Systems & Networks Peking University Beijing 100871 China Committee of Yuanpei Honors Program Peking University Beijing 100871 China Department of Electrical Engineering and computer science Peking University Beijing 100871 China

In recent years,much attention has been given to the increase in the Earth-Sun distance,with the modern rate reported as 5-15 m/cy on the basis of astronomical ***,traditional methods cannot measure the ancient leaving rates,so a myriad of research attempting to provide explanations were met with unmatched *** this paper we consider that the growth patterns on fossils could reflect the ancient Earth-Sun *** mechanical analysis of both the Earth-Sun and Earth-Moon systems,these patterns confirmed an increase in the Earth-Sun *** a large number of well-preserved specimens and new technology available,both the modern and ancient leaving rates could be measured with high precision,and it was found that the Earth has been leaving the Sun over the past 0.53.billion *** Earth's semi-major axis was 146 million kilometers at the beginning of the Phanerozoic Eon,equating to 97.6% of its current *** modern leaving rates are 5-14 m/cy,whereas the ancient rates were much *** results indicate a special expansion with an average expansion coefficient of 0.57H0 and deceleration in the form of Hubble *** the basis of experimental results,the Earth's semi-major axis could be represented by a simple formula that matches fossil measurements.

关键词：地球太阳古代距离生长模式实验石珊瑚量化

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Implementation of a multiple round quantum dense coding using nuclear magnetic resonance

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science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 706-715页

作者： ZHANG Jingfu1, XIE Jingyi2, WANG Chuan1, DENG Zhiwei3. LU Zhiheng4, & LONG Guilu1,5 1. Key Laboratory For Quantum Information and Measurements of MOE, Department of Physics, Tsinghua university, beijing 100084,china 2. Department of Materials {3. and Engineering, beijing Normal university, beijing 100875, china 3. Testing and Analytical Center, beijing Normal university, beijing 100875,china 4. Department of Physics, beijing Normal university, beijing 100875, china 5. Key Laboratory For atomic and Molecular Nano{3.s, Tsinghua university, beijing 100084,china 1. Key Laboratory For Quantum Information and Measurements of MOE Department of Physics Tsinghua University 100084 Beijing China 2. Department of Materials science and Engineering Beijing Normal University 100875 Beijing China 3. Testing and Analytical Center Beijing Normal University 100875 Beijing China 4. Department of Physics Beijing Normal University 100875 Beijing China 5. Key Laboratory For Atomic and Molecular Nanosciences Tsinghua University 100084 Beijing China

A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2m+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment.

关键词： quantum dense coding, multiple round, nuclear magnetic resorance

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Conformal isoparametric hypersurfaces with two distinct conformal principal curvatures in conformal space

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science china Mathematics 2010年第4期53卷 953-965页

作者： NIE ChangXiong 1,2,LI TongZhu 3.HE YiJun 4 & WU ChuanXi 5 1 Faculty of Mathematics and computer sciences,Hubei university,Wuhan 43.062,{3. 2 School of Mathematical sciences,Peking university,beijing 100871,{3. 3.Faculty of sciences,beijing Institute of technology,beijing 100081,{3. 4 School of Mathematical sciences,Shanxi university,Taiyuan 03.006,{3. 5 Institute of Mathematics,Hubei university,Wuhan 43.062,{3. 1. Faculty of Mathematics and computer sciences Hubei University Wuhan 430062 China2. School of Mathematical Sciences Peking University Beijing 100871 China3. Faculty of Sciences Beijing Institute of Technology Beijing 100081 China4. School of Mathematical Sciences Shanxi University Taiyuan 030006 China5. Institute of Mathematics Hubei University Wuhan 430062 China

The conformal geometry of regular hypersurfaces in the conformal space is *** classify all the conformal isoparametric hypersurfaces with two distinct conformal principal curvatures in the conformal space up to confor... 详细信息

关键词： Lorentz conformal geometry conformal invariants conformal isoparametric hypersurfaces

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Surface roughness and removal rate in magnetorheological finishing of a subsurface damage free surface

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Progress in Natural science:Materials International 2005年第6期15卷 538-544页

作者： CHENG Haobo1*, WANG Yingwei2, FENG Zhijing1 and CHENG Kai3.1. State Key Laboratory of Tribiology, Tsinghua university, beijing 100084, china 2. Department of Material {3.s, Changchun university of {3. and technology, Changchun 13.021, china 3. Faculty of Information and Engineering Systems, City Campus, Leeds LS1 3.E, UK) State Key Laboratory of Tribiology Tsinghua University Beijing 100084 China Department of Material sciences Changchun University of Science and Technology Changchun 130021 China Faculty of Information and Engineering Systems City Campus Leeds LS1 3HE UK

Based on computer-controlled optical surfacing, a new technique called magnetorheological finishing (MRF), is presented. The new technique combines the features of conventional loose abrasive machining with a wheel shaped polishing tool. The tool incorporates a host of features and has unprecedented fabricating versatility. The pre-polishing and fine polishing processes can be performed only by adjusting different parameters. The material removal function is studied theoretically and the results of simulation present a Gaussian distribution feature. Based on the established theoretical model, material removal rate experiments involving a parabolic mirror are designed and carried out to determine the effect of controllable parameters on size of the gap between the workpiece and the polishing wheel, rotating speed of the polishing wheel, concentration of volume fraction of non-magnetic particles and polishing time. Further experiments are carried out on the surface microstructure of the workpiece, the final surface roughness with an initial value of 10.98 nm reaches 1.22 nm root mean square (RMS) after 20 min of polishing. The subsurface damage experiment and the atomic force microscopy (AFM) measurement on the polished surface can also verify the feasibility of the MRF technique.

关键词： magnetorheological finishing surface roughness computer controlled optical surfacing subsurface damage removal function.

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