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Boosting Bootstrap FLD Subspaces in Classification

电子学报(英文版) 2008年第4期17卷 655-658页

作者： SHEN Daoyi YU Nenghai PANG Yanwei WANG Lei MOE-MS Key Laboratory of Multimedia Computing and Communication University of Science and Technology of China Hefei 230007 China Department of EEIS University of Science and Technology of China Hefei 230027 China School of Electronic Information Engineering Tianjin University Tianjin 300072 China

Propose a new ensemble learning algorithm based on Fisher linear discriminant analysis (FLD or LDA) and Adaboost.M2 for multi-class classification problem. On each iteration of boosting, a number of bootstrap training subsets are first sampled from the original training set according to the sample weights, and FLD is employed in each subset to construct a number of bootstrap FLD subspaces. Then the subspace with the minimum weighted K-nearest neighbor (KNN) pseudo-loss was selected to form the final strong classifier and update the sample weights. The main advantage of our algorithm is that its application is not restricted to the Gaussian assumption of data distribution, and the learning criterion is directly related to the minimum training error. Through the experiments on two real-world data sets, we demonstrate that our algorithm is superior to other techniques, especially for complex data distribution.

关键词：费希尔线性判别式分析整体学习引导程序分级

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A Stochastic Approximation Frame Algorithm with Adaptive Directions

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Numerical Mathematics(Theory,Methods and Applications) 2008年第4期1卷 460-474页

作者： Zi Xu Yu-Hong Dai Department of Mathematics College of Sciences Shanghai University Shang-hai 200444 PR. China. State Key Laboratory of Scientific and Engineering Computing Institute of Com-putational Mathematics and Scientific/Engineering Computing The Academy ofMathematics and Systems Science Chinese Academy of Sciences P.O.Box 2719Beijing 100190 P.R. China.

Stochastic approximation problem is to find some root or extremum of a nonlinear function for which only noisy measurements of the function are available. The classical algorithm for stochastic approximation problem is the Robbins-Monro （RM） algorithm, which uses the noisy evaluation of the negative gradient direction as the iterative direction. In order to accelerate the RM algorithm, this paper gives a flame algorithm using adaptive iterative directions. At each iteration, the new algorithm goes towards either the noisy evaluation of the negative gradient direction or some other directions under some switch criterions. Two feasible choices of the criterions are proposed and two corresponding frame algorithms are formed. Different choices of the directions under the same given switch criterion in the frame can also form different algorithms. We also proposed the simultanous perturbation difference forms for the two frame algorithms. The almost surely convergence of the new algorithms are all established. The numerical experiments show that the new algorithms are promising.

关键词： Stochastic approximation conjugate gradient adaptive directions.

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A posteriori error estimates of constrained optimal control problem governed by convection diffusion equations

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中国高等学校学术文摘·数学 2008年第3期3卷 415-442页

作者： Ningning YAN Zhaojie ZHOU State Key Laboratory of Scientific and Engineering Computing Institute of Systems cienceAcademy of Mathematics and System SciencesChinese Academy of SciencesBeijing 100190China

In this paper,we study a posteriori error estimates of the edge stabilization Galerkin method for the constrained optimal control problem governed by convection-dominated diffusion *** residual-type a posteriori error estimators yield both upper and lower bounds for control u measured in L2-norm and for state y and costate p measured in energy *** numerical examples are presented to illustrate the effectiveness of the error estimators provided in this paper.

关键词： Constrained optimal control problem convection dominated diffusion equation edge stabilization Galerkin method a posteriori error estimate

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Message from the IWPAPS 2008 workshop chair

Proceedings - 10th IEEE International Conference on High Per...

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Proceedings - 10th IEEE International Conference on High Performance computing and Communications, HPCC 2008 2008年 xxiv页

作者： Linbo, Zhang State Key Laboratory of Scientific and Engineering Computing CAS China

No abstract available

ISBN: (纸本)9780769533520

No abstract available

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Dynamic Load Balancing on Adaptive Unstructured Meshes

Dynamic Load Balancing on Adaptive Unstructured Meshes

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IEEE International Conference on High Performance computing and Communications (HPCC)

作者： Hui Liu State Key Laboratory of Scientific and Engineering Computing CAS Beijing China

In this paper the work on implementing two mesh partitioning algorithms, the refinement-tree based partitioning algorithm and the space-filling curve partitioning algorithm, in the parallel adaptive finite element toolbox PHG (parallel hierarchical grid) is presented. These algorithms are used for both initial mesh partitioning and mesh repartitioning for dynamical load balancing in adaptive finite element computations. In the implementations improved algorithms are designed. Partitioning time and quality of our code are compared with existing publicly available mesh or graph partitioners, including ParMETIS and Zoltan, through some numerical examples.

关键词： Finite element methods Partitioning algorithms Indexes Face Complexity theory Algorithm design and analysis Classification algorithms

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Image quality assessment metrics with Radon transform

Image quality assessment metrics with Radon transform

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IEEE International Conference on Systems, Man and Cybernetics

作者： Jianxin Pang Rong Zhang Hui Zhang Xuan Huang Zhenkai Liu MOE-Microsoft Key Laboratory of Multimedia Computing and Communication Department of Electronic Engineering and Information Science University of Science and Technology Hefei Anhui China

Objective image quality assessment (QA) is a fundamental and challenging job in image processing which evaluates the image quality consistently with human perception automatically. Generally, an image can be segmented into two kinds of areas: structure and texture. And structural information plays a much more important role between the two. The pixels, edges and shape with directional characteristic contribute much more to the structural information. In this paper, the structural information is modeled as the energy of directional projection, which is shown in a directional projection-based map that is built by Radon transform. On the assumption that any image's distortion could be modeled as the difference between the directional projection-based maps of reference and distortion images, we propose a new objective quality assessment method with Radon transform for full reference model, and we also try to explore the feasibility to develop the image QA metrics with scalable efficiency and computational cost. Experimental results show that the proposed metrics are well consistent with the subjective quality score.

关键词： Image quality Humans Image processing PSNR Quality assessment Computational efficiency Error analysis Signal to noise ratio Image storage Laboratories

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Efficient Parallel Adaptive Computation of 3D Time-Harmonic Maxwell's Equations Using the Toolbox PHG

Efficient Parallel Adaptive Computation of 3D Time-Harmonic ...

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IEEE International Conference on High Performance computing and Communications (HPCC)

作者： Tao Cui State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics Academy of Mathematics and Systems Science Chinese Academy and Sciences Beijing China

PHG (parallel hierarchical grid) is a scalable parallel adaptive finite element toolbox under active developmentat the State key laboratory of scientific and engineering computing, Chinese Academy of Sciences. This paper demonstrates its application to adaptive finite element computations of electromagnetic problems. Two examples on solving the time harmonic Maxwell's equations are shown. Results of some large scale adaptive finite element simulations with up to 1 billion degrees of freedom and using up to 2048 CPUs are presented.

关键词： Finite element methods Equations Mathematical model Linear systems Harmonic analysis Algorithm design and analysis Laboratories

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Doctored JPEG image detection

Doctored JPEG image detection

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IEEE International Conference on Multimedia and Expo (ICME)

作者： Weihai Li Nenghai Yu Yuan Yuan MOE-Microsoft Key Laboratory of Multimedia Computing and Communication University of Science and Technology Hefei China School of Engineering and Applied Science Aston University Birmingham UK

Nowadays, digital images can be easily modified by using software. In this paper, a new blind approach is proposed to detect copy-paste trail in a doctored JPEG image, i.e., to check whether a copied area came from the same image or not. When a copy-paste procedure is done on an image, especially adding or hiding an object, the block artifact grid contained in the copy-pasted slice is moved together. Since a slice must be placed properly in the target image to avoid obvious vision flaw, the grid in the slice mismatches to the original grid in the target image normally. Our approach utilizes the mismatch information of block artifact grid as a clue of copy-paste forgery. Experiment results demonstrate the efficiency of the proposed approach.

关键词： Transform coding Medical services Forgery Discrete cosine transforms Image coding Algorithm design and analysis Barium

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Preconditioners for higher order edge finite element discretizations of Maxwell's equations

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Science China Mathematics 2008年第8期51卷 1537-1548页

作者： ZHONG LiuQiang1,2,SHU Shi1,2,SUN DuDu3&TAN Lin4 1School of Mathematical and Computational Sciences,Xiangtan University,Xiangtan 411105,China 2Hunan key laboratory for Computation and Simulation in Science and engineering,Xiangtan 411105,China 3Institute of Computational Mathematics and scientific/engineering computing,Academy of Mathematicsand Systems Science,Graduate University of Chinese Academy of Sciences,Chinese Academy Sciences,P.O.Box 2719,Beijing 100190,China 4Department of Math-Physics,Nanhua University,Hengyang 421001,China 1. School of Mathematical and Computational Sciences Xiangtan University Xiangtan 411105 China 2. Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan 411105 China 3. Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Graduate University of Chinese Academy of Sciences Chinese Academy Sciences P.O. Box 2719 Beijing 100190 China 4. Department of Math-Physics Nanhua University Hengyang 421001 China

In this paper,we are concerned with the fast solvers for higher order edge finite element discretizations of Maxwell's *** present the preconditioners for the first family and second family of higher order N′ed′elec element equations,*** combining the stable decompositions of two kinds of edge finite element spaces with the abstract theory of auxiliary space preconditioning,we prove that the corresponding condition numbers of our preconditioners are uniformly bounded on quasi-uniform *** also present some numerical experiments to demonstrate the theoretical results.

关键词： preconditioner higher order edge finite element stable decomposition

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Novel DCT-based real-valued discrete Gabor transform

Novel DCT-based real-valued discrete Gabor transform

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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： Liang Tao Hon Keung Kwan MOE Key Laboratory of Intelligent Computing & Signal Processing Anhui University Hefei Anhui China Department of Electrical and Computer Engineering University of Windsor Windsor ONT Canada

The traditional DCT-based real-valued discrete Gabor transform (RGDT) was limited to the critical sampling case. The biorthogonality relationship between the analysis window and the synthesis window for the transform has not been unveiled. To overcome those drawbacks, this paper proposes a novel DCT-based real-valued discrete Gabor transform, which can be applied under both the critical sampling condition and the over-sampling condition. And the biorthogonality relationship between the analysis window and the synthesis window for the transform is also proved in this paper. Because it only involves real operations and can utilize fast DCT and DDCT algorithms for fast computation, it facilitates computation and implementation by hardware and/or software compared to the traditional complex-valued discrete Gabor transform.

关键词： Discrete transforms Sampling methods Hardware Discrete cosine transforms Software algorithms Biomedical signal processing Signal sampling Signal synthesis Signal processing algorithms Parallel algorithms

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