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Blind image deconvolution using sparse and redundant representation

OPTIK 2014年第23期125卷 6942-6945页

作者： Ma, Long Zhang, Rongzhi Qu, Zhiguo Lu, Fangyun Xu, Rong State Key Lab Astronaut Dynam Xian 710043 Shanxi Peoples R China Natl Univ Def Technol Changsha 410073 Hunan Peoples R China Air Force Early Warning Acad Wuhan 430019 Hubei Peoples R China

This work devotes to the image deconvolution problem that restores clear image from its blurred and noisy measurements with little prior about the blur. A deconvolution method based on sparse and redundant representation theory is developed in this paper. It firstly represents the blur and image over different redundant dictionaries and imposes sparsity constraint to their representation coefficients respectively, then alternately estimates them using an iterative algorithm employing optimization technique. Experimental results on astronomical images show that the proposed method can achieve as good performance as the method requiring a known blur, which demonstrates its effectiveness. (C) 2014 Elsevier GmbH. All rights reserved.

关键词： Deconvolution Image debluring Blur estimation Sparse and redundant representation (SRR) iterative algorithm

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Regression model for tuning the PID controller with fractional order time delay system

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AIN SHAMS ENGINEERING JOURNAL 2014年第4期5卷 1071-1081页

作者： Agnihotri, S. P. Waghmare, Laxman Madhavrao SGGS Inst Engn & Technol Nanded India

In this paper a regression model based for tuning proportional integral derivative (PID) controller with fractional order time delay system is proposed. The novelty of this paper is that tuning parameters of the fractional order time delay system are optimally predicted using the regression model. In the proposed method, the output parameters of the fractional order system are used to derive the regression function. Here, the regression model depends on the weights of the exponential function. By using the iterative algorithm, the best weight of the regression model is evaluated. Using the regression technique, fractional order time delay systems are tuned and the stability parameters of the system are maintained. The effectiveness and feasibility of the proposed technique is demonstrated through the MATLAB/Simulink platform, as well as testing and comparison using the classical PID controller, Ziegler-Nichols tuning method, Wang tuning method and curve fitting technique base tuning method. (C) 2014 Production and hosting by Elsevier B.V.

关键词： Regression model PID controller iterative algorithm Fractional order Time delay and system

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A new voxellation scheme for iterative CBCT reconstruction with less computational cost: Polar voxel design of an isosceles-triangle shape

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JOURNAL OF THE KOREAN PHYSICAL SOCIETY 2014年第7期65卷 1128-1133页

作者： Lee, Minsik Cho, Hyosung Hong, Daeki Je, Uikyu Park, Yeonok Park, Chulkyu Cho, Heemoon Choi, Sungil Koo, Yangseo Yonsei Univ Dept Radiol Sci Wonju 220710 South Korea Yonsei Univ VYS Res Ctr Wonju 220710 South Korea

We propose a new voxellation scheme for iterative cone-beam computed tomography (CBCT) reconstruction with less computational cost. Here, the voxel configuration is designed with an isosceles-triangle shape by using polar coordinates, exploiting the rotational symmetries inherent to the CBCT acquisition geometry and keeping the uniformity of the voxel size as well. By using polar symmetries, we can reduce the size of the system matrix by a factor corresponding to the number of acquired projections, which speeds up the construction of the system matrix and, thus, allows iterative methods to be applied to practical applications within a reasonable reconstruction time. In this study, we implemented an efficient algorithm to reconstruct the system matrix based upon the proposed voxellation scheme and incorporated it into a built-in iterative CBCT reconstruction algorithm based the gradient-projection Barzilai-Borwein (GPBB) method, and we performed systematic simulation works to investigate the imaging characteristics. Our results indicate that the voxellation scheme we proposed in study seems to be effective in reducing the computational time and the memory burden considerably.

关键词： Polar coordinate Isosceles triangle System matrix iterative algorithm

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On the Information Theoretic Performance Comparison of Causal Video Coding and Predictive Video Coding

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IEEE TRANSACTIONS ON INFORMATION THEORY 2014年第3期60卷 1428-1446页

作者： Yang, En-Hui Zheng, Lin He, Da-Ke Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada BlackBerry Waterloo ON N2L 5S8 Canada

Causal video coding is a coding paradigm where video source frames X-1, X-2,..., X-N are encoded in a frame-by- frame manner, the encoder for each frame can use all previous source frames and all previous encoded frames, and the corresponding decoder can use only all previous encoded frames. In the special case where the encoder for each frame X-k is further restricted to enlist help only from all previous encoded frames, causal video coding is reduced to predictive video coding, which all MPEG-series and H-series video coding standards proposed so far are based upon. In this paper, we compare the rate distortion performance of causal video coding with that of predictive video coding from an information theoretic perspective by modeling each frame Xk itself as a source X-k = {X-k(i)}(i = 1)(infinity).Let R-c(*) (D-1,..., D-N) (R-p(*)(D-1,..., D-N), respectively) denote the minimum total rate required to achieve a given distortion level D-1,..., D-N in causal video coding (predictive video coding, respectively). We first show that like R-c(*) (D-1,..., D-N), for jointly stationary and totally ergodic sources X-1, X-2,..., X-N, R-p(*)(D-1,..., D-N) is equal to the infimum of the nth order total rate distortion function Rp, n(D-1,..., D-N) over all n, where R-p(*), n(D-1,..., D-N) itself is given by the minimum of an information quantity over a set of auxiliary random variables. We then prove that if the jointly stationary and totally ergodic sources X-1,..., X-N form a (first-order) Markov chain, we have R-p(*)(D-1,..., D-N) = R-c(*) (D-1,..., D-N). However, this is not true in general if X-1,..., X-N do not form a (first-order) Markov chain. Specifically, we demonstrate that for independent and identically distributed vector source (X-1,..., X-N), if X-1,..., X-N do not form a (first-order) Markov chain, then under some conditions on source frames and distortion, R-c(*) (D-1,..., D-N) is strictly less than R-p(*)(D-1,..., D-N) in general. Our techniques allow us to c

关键词： Causal video coding iterative algorithm more and less coding theorem predictive video coding rate distortion theory stationary ergodic sources

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Finite iterative method for solving coupled Sylvester-transpose matrix equations

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JOURNAL OF APPLIED MATHEMATICS AND COMPUTING 2014年第1-2期46卷 351-372页

作者： Song, Caiqin Feng, Jun-e Wang, Xiaodong Zhao, Jianli Shandong Univ Sci & Technol Coll Informat Sci & Engn Qingdao 266590 Peoples R China Shandong Univ Sch Math Jinan 250100 Peoples R China Harbin Inst Technol Sch Astronaut Harbin 150001 Peoples R China Liaocheng Univ Coll Math Sci Liaocheng 252059 Peoples R China

This paper is concerned with solutions to the so-called coupled Sylvester-transpose matrix equations, which include the generalized Sylvester matrix equation and Lyapunov matrix equation as special cases. By extending the idea of conjugate gradient method, an iterative algorithm is constructed to solve this kind of coupled matrix equations. When the considered matrix equations are consistent, for any initial matrix group, a solution group can be obtained within finite iteration steps in the absence of roundoff errors. The least Frobenius norm solution group of the coupled Sylvester-transpose matrix equations can be derived when a suitable initial matrix group is chosen. By applying the proposed algorithm, the optimal approximation solution group to a given matrix group can be obtained by finding the least Frobenius norm solution group of new general coupled matrix equations. Finally, a numerical example is given to illustrate that the algorithm is effective.

关键词： Coupled Sylvester-transpose matrix equation Least Frobenius norm solution iterative algorithm Optimal approximation solution Spectral norm

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RERS2013: A NEW HIGH-PRECISION RIGID EARTH ROTATION SERIES

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ARTIFICIAL SATELLITES-JOURNAL OF PLANETARY GEODESY 2014年第3期49卷 160-177页

作者： Pashkevich, V. V. RAS Cent Pulkovo Astron Observ Pulkovskoe Shosse 65-1 St Petersburg 196140 Russia

In the previous investigation (Pashkevich, 2013) the high-precision Rigid Earth Rotation Series (designated RERS2012) dynamically adequate to the JPL DE406/LE406 (Standish, 1998) ephemeris over 2000 and 6000 years were constructed. The main aim of present research is improvement of the Rigid Earth Rotation Series RERS2012 by using the JPL DE422/LE422 (Folkner, 2011) ephemeris, and as a result is produced construction of the new high-precision Rigid Earth Rotation Series dynamically adequate to the JPL DE422/LE422 ephemeris over 2000 and 6000 years. The discrepancies in Euler angles between the high-precision numerical solutions and the semi-analytical solutions of the rigid Earth rotation problem are investigated by least squares and spectral analysis methods using the iterative algorithm (Pashkevich, 2013). In order to demonstrate the good convergence of this iterative algorithm are constructed additional solutions of the rigid Earth rotation dynamically adequate to the JPL DE422/LE422 over 2000 years by improvement solutions SMART97 (Bretagnon et al., 1998) and S9000 (Pashkevich and Eroshkin, 2005a). As the results of this investigation, the new improved high-precision Rigid Earth Rotation Series RERS2013 dynamically adequate to the DE422/LE422 ephemeris over 2000 and 6000 years have been constructed. The discrepancies in Euler angles between the numerical solution and RERS2013 do not surpass: 4 mu as over 2000 years, 1 mas over 6000 years. The RERS2013 series is more accurate than the RERS2012 series, which is dynamically adequate to the DE406/LE406 ephemeris. The good convergence of the iterative algorithm of this study has been confirmed.

关键词： the rigid Earth rotation ephemeris iterative algorithm least-squares method spectral analysis method

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Reduced-Complexity Coordinated Beamforming for Multicell Downlink Max-Min SINR Problem

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IEEE WIRELESS COMMUNICATIONS LETTERS 2014年第4期3卷 353-356页

作者： Hou, Jiancao Ma, Yi Yi, Na Tafazolli, Rahim Univ Surrey Ctr Commun Syst Res Guildford GU2 7XH Surrey England

This letter presents a reduced-complexity algorithm for coordinated beamforming aimed at solving the multicell down-link max-min signal-to-interference-plus-noise problem under per-base-station power constraints. It is shown that the proposed algorithm can achieve close performance to the optimum algorithm with faster convergence and lower complexity.

关键词： Coordinated beamforming iterative algorithm max-min SINR multicell downlink per-BS power constraint

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General iterative methods for equilibrium and constrained convex minimization problem

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OPTIMIZATION 2014年第9期63卷 1367-1385页

作者： Tian, Ming Liu, Lei Civil Aviat Univ China Coll Sci Tianjin 300300 Peoples R China Tianjin Key Lab Adv Signal Proc Civil Aviat Univ China Tianjin 300300 Peoples R China

The gradient-projection algorithm (GPA) plays an important role in solving constrained convex minimization problems. Based on Marino and Xu's method [G. Marino and H.-K. Xu, A general method for nonexpansive mappings in Hilbert space, J. Math. Anal. Appl. 318 (2006), pp. 43-52], we combine GPA and averaged mapping approach to propose implicit and explicit composite iterative algorithms for finding a common solution of an equilibrium and a constrained convex minimization problem for the first time in this article. Under suitable conditions, strong convergence theorems are obtained.

关键词： iterative algorithm equilibrium problem constrained convex minimization variational inequality

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Multi-step extragradient method with regularization for triple hierarchical variational inequalities with variational inclusion and split feasibility constraints

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JOURNAL OF INEQUALITIES AND APPLICATIONS 2014年第1期2014卷 1-40页

作者： Ceng, Lu-Chuan Pang, Chin-Tzong Wen, Ching-Feng Shanghai Normal Univ Dept Math Shanghai 200234 Peoples R China Yuan Ze Univ Dept Informat Management Innovat Ctr Big Data & Digital Convergence Chungli 32003 Taiwan Kaohsiung Med Univ Ctr Fundamental Sci Kaohsiung 80708 Taiwan

By combining Korpelevich's extragradient method, the viscosity approximation method, the hybrid steepest-descent method, Mann's iteration method, and the gradient-projection method with regularization, a hybrid multi-step extragradient algorithm with regularization for finding a solution of triple hierarchical variational inequality problem is introduced and analyzed. It is proven that under appropriate assumptions, the proposed algorithm converges strongly to a unique solution of a triple hierarchical variational inequality problem which is defined over the set of solutions of a hierarchical variational inequality problem defined over the set of common solutions of finitely many generalized mixed equilibrium problems (GMEP), finitely many variational inclusions, fixed point problems, and the split feasibility problem (SFP). We also prove the strong convergence of the proposed algorithm to a common solution of the SFP, finitely many GMEPs, finitely many variational inclusions, and the fixed point problem of a strict pseudocontraction. The results presented in this paper improve and extend the corresponding results announced by several others.

关键词： triple hierarchical variational inequalities hierarchical variational inequalities variational inclusions split feasibility problems fixed point problems iterative algorithm strong convergence result

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iterative Scheme of Finding a Spectrum of the Product of Two Non-Commutative Operators

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NUMERICAL ANALYSIS AND APPLICATIONS 2014年第4期7卷 345-358页

作者： Tarakanov, V. I. Lysenkova, S. A. Nesterenko, M. V. Surgut State Univ Pr Lenina 1 Tyumen 628400 Russia

We consider spectral features and an iterative scheme of finding a spectrum of the product of two non-commutative partially symmetric operators in the Hilbert space H. In this case, it is assumed that one of the operators is compact, the second one not necessarily being compact and even bounded in H. Numerical implementation of the iterative scheme for finding the operator spectrum of the problem of eigen-oscillations of the Rayleigh beam is presented.

关键词： operator spectrum iterative algorithm

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