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iterative algorithm of scattering correction for quantitative neutron digital imaging system

He Jishu/Nuclear Techniques 2008年第11期31卷 824-829页

作者： Wei, Biao Ma, Xiaoxin Jin, Wei Feng, Peng Mi, Deling Key Laboratory of Opto-Electronics Technology and Systems Chongqing University Chongqing 400044 China College of Information Science and Engineering Ningbo University Ningbo 315211 China

Quantitative neutron digital imaging is an important means of NDT (Non-destructive Testing) and NDE (Non-destructive Evaluation). Scattering neutrons have an adverse effect to quality of neutron images when quantitative analysis has to be made in NDT. For quantitative neutron imaging instrument, the principle of imaging degradation caused by neutron scattering is analyzed, and the scattering degradation process is represented by the supposition of PSF (Point Spread Function) superposition. On the basis of constructed PSF model of neutron imaging, a space-domain iterative algorithm applied to scattering correction for this instrument is proposed. The result shows that after correction, for different shapes of H2O samples at different sample-to-detector distances, the scattering component affecting imaging quality of the instrument is apparently restrained, and thickness of the samples evaluated from the processed image approaches their real thickness. This algorithm proves to be practical and effective.

关键词： H2O sample iterative algorithm Neutron scattering correction Point spread function Quantitative neutron imaging instrument

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Hierarchical gradient based iterative parameter estimation algorithm for multivariable output error moving average systems

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COMPUTERS & MATHEMATICS WITH APPLICATIONS 2011年第3期61卷 672-682页

作者： Zhang, Zhening Ding, Feng Liu, Xinggao Jiangnan Univ Key Lab Adv Proc Control Light Ind Minist Educ Sch IoT Engn Wuxi 214122 Peoples R China Zhejiang Univ State Key Lab Ind Control Technol Dept Control Sci & Engn Hangzhou 310027 Peoples R China

According to the hierarchical identification principle, a hierarchical gradient based iterative estimation algorithm is derived for multivariable output error moving average systems (i.e., multivariable OEMA-like models) which is different from multivariable CARMA-like models. As there exist unmeasurable noise-free outputs and unknown noise terms in the information vector/matrix of the corresponding identification model, this paper is, by means of the auxiliary model identification idea, to replace the unmeasurable variables in the information vector/matrix with the estimated residuals and the outputs of the auxiliary model. A numerical example is provided. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： iterative algorithm Jacobi iteration Matrix equation Gradient search Parameter estimation iterative identification Hierarchical identification Multivariable OEMA-like model Multivariable CARMA-like model

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Rate Distortion Theory for Causal Video Coding: Characterization, Computation algorithm, Comparison, and Code Design

Rate Distortion Theory for Causal Video Coding: Characteriza...

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作者： Zheng, Lin University of Waterloo

学位级别：master

Due to the sheer volume of data involved, video coding is an important application of lossy source coding, and has received wide industrial interest and support as evidenced by the development and success of a series of video coding standards. All MPEG-series and H-series video coding standards proposed so far are based upon a video coding paradigm called predictive video coding, where video source frames X?,i=1,2,...,N, are encoded in a frame by frame manner, the encoder and decoder for each frame X?, i =1, 2, ..., N, enlist help only from all previous encoded frames Sj, j=1, 2, ..., *** this thesis, we will look further beyond all existing and proposed video coding standards, and introduce a new coding paradigm called causal video coding, in which the encoder for each frame X? can use all previous original frames Xj, j=1, 2, ..., i-1, and all previousencoded frames Sj, while the corresponding decoder can use only allprevious encoded frames. We consider all studies, comparisons, and designs on causal video codingfrom an information theoreticpoint of view. Let R*c(D?,...,D_N) (R*p(D?,...,D_N), respectively) denote the minimum total rate required to achieve a given distortion level D?,...,D_N > 0 in causal video coding (predictive video coding, respectively). A novel computationapproach is proposed to analytically characterize, numerically compute, and compare the minimum total rate of causal video coding R*c(D?,...,D_N) required to achieve a given distortion (quality) level D?,...,D_N > ***, we first show that for jointly stationary and ergodicsources X?, ..., X_N, R*c(D?,...,D_N) is equalto the infimum of the n-th order total rate distortion functionR_{c,n}(D?,...,D_N) over all n, whereR_{c,n}(D?,...,D_N) itself is given by the minimum of aninformation quantity over a set of auxiliary random variables. Wethen present an iterative algorithm for computingR_{c,n}(D?,...,D_N) and demonstrate the convergence of thealgorithm to the global minimum. The gl

关键词： causal video coding iterative algorithm multi-user information theory predictive video coding rate distortion theory more and less coding theorem

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A numerical algorithm based on a variational iterative approximation for the discrete Hamilton-Jacobi-Bellman (HJB) equation

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COMPUTERS & MATHEMATICS WITH APPLICATIONS 2011年第4期61卷 901-907页

作者： Chen, Guanghua Chen, Guangming Shanghai Jiao Tong Univ Coll Econ & Management Shanghai 200052 Peoples R China Shanghai Jiao Tong Univ Sch Mech Engn Shanghai 200240 Peoples R China

This paper presents a numerical algorithm based on a variational iterative approximation for the Hamilton-Jacobi-Bellman equation, and a domain decomposition technique based on this algorithm is also studied. The convergence theorems have been established. Numerical results indicate the efficiency and accuracy of the methods. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Quasivariational inequality system Hamilton-Jacobi-Bellman equation iterative algorithm Monotone convergence

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AN iterative algorithm FOR OPTIMAL DESIGN OF NON-FREQUENCY-SELECTIVE FIR DIGITAL FILTERS

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Journal of Electronics(China) 2008年第5期25卷 667-672页

作者： Tian Xinguang Duan Miyi Sun Chunlai Liu Xin Institute of Computing Technology Beijing Jiaotong University Beijing 100029 China Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

This paper proposes a novel iterative algorithm for optimal design of non-frequency-selective Finite Impulse Response(FIR) digital filters based on the windowing *** from the traditional optimization concept of adjusting the window or the filter order in the windowing design of an FIR digital filter,the key idea of the algorithm is minimizing the approximation error by succes-sively modifying the design result through an iterative procedure under the condition of a fixed window *** the iterative procedure,the known deviation of the designed frequency response in each iteration from the ideal frequency response is used as a reference for the next *** the approximation error can be specified variably,the algorithm is applicable for the design of FIR digital filters with different technical requirements in the frequency domain.A design example is employed to illustrate the efficiency of the algorithm.

关键词： Finite Impulse Response （FIR） digital filters Optimal design Windowing method Approximation error iterative algorithm

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Generating Functional Analysis of iterative algorithms for Compressed Sensing

Generating Functional Analysis of Iterative Algorithms for C...

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IEEE International Symposium on Information Theory (ISIT)

作者： Mimura, Kazushi Hiroshima City Univ Dept Informat Sci Hiroshima 7313194 Japan

ISBN: (纸本)9781457705953

It has been shown that approximate message passing algorithm is effective in reconstruction problems for compressed sensing. To evaluate dynamics of such an algorithm, the state evolution (SE) has been proposed. If an algorithm can cancel the correlation between the present messages and their past values, SE can accurately tract its dynamics via a simple one-dimensional map. In this paper, we focus on dynamics of algorithms which cannot cancel the correlation and evaluate it by the generating functional analysis (GFA), which allows us to study the dynamics by an exact way in the large system limit.

关键词： algorithm design and analysis Approximation algorithms Compressed sensing Correlation GFA Heuristic algorithms iterative methods Random variables SE approximate message passing algorithm compressed sensing correlation theory functional analysis generating functional analysis iterative algorithm iterative methods one-dimensional map signal reconstruction state evolution

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A New Optimal Scheme for Solving Nonlinear Heat Conduction Problems

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CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES 2012年第4期88卷 269-291页

作者： Chang, Chih-Wen Liu, Chein-Shan Natl Ctr High Performance Comp Comp Technol Integrat Div Taichung 40763 Taiwan Natl Taiwan Univ Dept Civil Engn Taipei 10617 Taiwan

In this article, we utilize an optimal vector driven algorithm (OVDA) to cope with the nonlinear heat conduction problems (HCPs). From this set of nonlinear ordinary differential equations, we propose a purely iterative scheme and the spatial-discretization of finite difference method for revealing the solution vector x, without having to invert the Jacobian matrix D. Furthermore, we introduce three new ideas of bifurcation, attracting set and optimal combination, which are restrained by two parameters gamma and alpha. Several numerical instances of nonlinear systems under noise are examined, finding that the OVDA has a fast convergence rate, great computation accuracy and efficiency.

关键词： Nonlinear algebraic equations Nonlinear heat conduction equation iterative algorithm Optimal vector driven algorithm (OVDA) Invariant manifold

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iterative algorithm TO COMMON FIXED POINTS OF INFINITE NONEXPANSIVE MAPPINGS IN BANACH SPACES

ITERATIVE ALGORITHM TO COMMON FIXED POINTS OF INFINITE NONEX...

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2008 International Conference on Machine Learning and Cybernetics(2008机器学习与控制论国际会议)

作者： WEI LI LI-LING DUAN School of Mathematics and Statistics Hebei University of Economics and Business Shijiazhuang 050061 China

Finding iterative algorithms to approximate fixed points for nonexpansive mappings is a very active topic in a number of mathematical and engineering areas, in particular, in image recovery and signal processing. Considerable research efforts have been devoted to the study of this area in recent years. By now, there already exist some algorithms, but they are not quite enough to deal with problems of finding common fixed points of infinite nonexpansive mappings. In this paper, a more general form of iterative algorithm is introduced which is proved to be strongly convergent to common fixed point of infinite nonexpansive mappings in a real strictly convex and uniformly smooth Banach space by using some new techniques.

关键词： Nonezpansive mappings fized points iterative algorithm Banach space

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PRECODING AND DECODING DESIGN FOR TWO-WAY MIMO AF MULTIPLE-RELAY SYSTEM

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Journal of Electronics(China) 2012年第Z2期 177-189页

作者： Zhi Hui Yang Longxiang Zhu Hongbo (Jiangsu Key Lab of Wireless Communication, Nanjing University of Posts and Telecommunications, Nanjing 210003, China)

In this paper, a joint precoding and decoding design scheme is proposed for two-way Multiple-Input Multiple-Output (MIMO) multiple-relay system. The precoding and decoding matrices are jointly optimized based on Minimum Mean-Square-Error (MMSE) criteria under transmit power constraints. The optimization problem is solved by using a convergent iterative algorithm which in-cludes four sub-problems. It is shown that due to the difficulty of the block diagonal nature of the relay precoding matrix, sub-problem two cannot be solved with existing methods. It is then solved by converting sub-problem two into a convex optimization problem and a simplified method is proposed to reduce the computational complexity. Simulation results show that the proposed scheme can achieve lower Bit Error Rate (BER) and larger sum rate than other schemes. Furthermore, the BER and the sum rate performance can be improved by increasing the number of antennas for the same number of relays or increasing the number of relays for the same number of antennas.

关键词： Precoding and decoding design iterative algorithm Two-way relaying Bit Error Rate (BER) Sum rate

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Study on model and algorithm of inventory routing problem

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Physics Procedia 2012年 24卷 1031-1037页

作者： Fengjiao Wan School of Business Jianghan University 430056WuhanHubeiChina

Vehicle routing problem(VRP) is one of important research in the logistics system. Nowadays, there are many researches on the VRP, but their don’t consider the cost of inventory. Thus, the conclusion doesn’t meet reality. This paper studies on the inventory routing problem (IRP)and uses one target function to describe these two conflicting problems, which are very important in the logistics optimization. The paper establishes the model of single client and many clients’ inventory routing problem. An optimizing iterative algorithm is presented to solve the model. According to the model we can confirm the best quantity, efficiency and route of delivery. Finally, an example is given to illustrate the efficiency of model and algorithm.

关键词： vehicle routing problem inventory routing problem iterative algorithm

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