We have investigated the p-multigrid iterative method for solving p = 1, 2, and 4 discontinuous Galerkin approximations to the Enter equations where p is the degree of the approximating polynomial. For comparison, we ...
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We have investigated the p-multigrid iterative method for solving p = 1, 2, and 4 discontinuous Galerkin approximations to the Enter equations where p is the degree of the approximating polynomial. For comparison, we have also investigated agglomeration multigrid for p = 0 approximations. Block diagonal, line, and sweeping relaxation schemes were examined. The convergence rate to a uniform flow on a structured mesh was analyzed as a function of the flow angle relative to the mesh, grid resolution, underrelaxation factor used, and Mach number. The result,;show that, even for this simplified problem, many of these schemes do not perform well. For p = 0, which corresponds to a conventional finite volume discretization, only the block symmetric Gauss-Seidel line relaxation and the Gauss-Seidel alternate direction line relaxation performed well under all conditions. For p > 0, all schemes converged slower than the corresponding p = 0 case. Furthermore, all of the schemes were more sensitive to flow angle and Mach number than with p = 0. We also found that two-level p-multigrid performs anomalously for p = I to 0. This behavior is illustrated and explained.
In this paper, we extend the auxiliary variational inequality technique due to Ding and Yao [X.P. Ding, J.C. Yao, Existence and algorithm of solutions for mixed quasi-variational-like inclusions in Banach spaces, Comp...
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In this paper, we extend the auxiliary variational inequality technique due to Ding and Yao [X.P. Ding, J.C. Yao, Existence and algorithm of solutions for mixed quasi-variational-like inclusions in Banach spaces, Comput. Math. Appl. 49 (2005) 857-869] to develop iterative algorithms for finding the approximate solutions of a mixed quasi-variational-like inclusion problem (in short, MQVLIP) in the setting of Banach spaces. We first establish a result on the existence of a solution of the equilibrium problem by virtue of the Fan-KKM lemma. Then by using this result and a result by Ding and Tan [X.P. Ding, K.K. Tan, A minimax inequality with applications to existence of equilibrium point and fixed point theorems, Colloq. Math. 63 (2) (1992) 233-247], we derive the existence of a unique solution of MQVLIP and the existence of approximate solutions generated by the proposed algorithms. Moreover, we also provide the new criteria for convergence of approximate solutions to the exact solution of MQVLIP. (C) 2008 Elsevier Ltd. All rights reserved.
Image restoration problems are often solved by finding the minimizer of a suitable objective function consisting of a data-fitting term and a regularization term. In this paper, we consider the data-fitting term measu...
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Image restoration problems are often solved by finding the minimizer of a suitable objective function consisting of a data-fitting term and a regularization term. In this paper, we consider the data-fitting term measured in the $\ell$1 norm to handle non-Gaussian additive noise and the regularization term given by the total variation (TV) to restore image edges. We propose a new algorithm for this image restoration problem by making use of new variables to modify the data-fitting term and the TV regularization term. An alternating minimization method based on the new formulation is employed to restore blurred and noisy images. Our experimental results show that the quality of restored images by the proposed method is competitive with those restored by the other tested methods. We also show the convergence of the alternating minimization algorithm and demonstrate that the proposed algorithm is very efficient.
A novel double-image encryption algorithm is proposed, which can simultaneously encrypt two images into a single one as the amplitude of a fractional Fourier transform with two different groups of fractional orders. T...
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A novel double-image encryption algorithm is proposed, which can simultaneously encrypt two images into a single one as the amplitude of a fractional Fourier transform with two different groups of fractional orders. The two original images can be retrieved independently by fractional Fourier transforms with two different groups of fractional orders, one public phase mask, and two different private phase masks. The proposed approach can enlarge the key space, achieve faster convergence in the iterative process, and avoid cross-talk between the two images in reconstruction. Numerical simulations are presented to verify its validity and efficiency.
A method for the application of the MIMO iterative waterfilling algorithm for broadband channels is presented. The modified game-theoretic problem formulation and its Nash equilibrium are presented, along with conditi...
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A method for the application of the MIMO iterative waterfilling algorithm for broadband channels is presented. The modified game-theoretic problem formulation and its Nash equilibrium are presented, along with conditions for its existence and uniqueness and for the convergence of the distributed algorithm. The method is verified using a simple design example. The performance of the MIMO iterative waterfilling algorithm in the presence of errors in the channel state information (CSI) is also presented.
To solve the electrical capacitance tomography(ECT)technology"soft field"effect and pathological problem,a Quasi-Newton new algorithm for electrical capacitance tomography is *** the basis of analyzing ECT s...
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To solve the electrical capacitance tomography(ECT)technology"soft field"effect and pathological problem,a Quasi-Newton new algorithm for electrical capacitance tomography is *** the basis of analyzing ECT system measurement principle, constructing corrector formula of secant approximation algorithm in second-order information items of objective *** feasibility of using this algorithm for ECT problems is also *** shows that it is easy to meet the convergence condition and error of image reconstruction is *** results and simulation data indicate that the algorithm can provide high quality images and favorable stabilization compared with LBP and conjugate gradient algorithms and this new algorithm presents a feasible and effective way to research on image reconstruction algorithm for Electrical Capacitance Tomography System.
＜正＞In this paper,an iterative high-resolution DOA algorithm is proposed for DOA estimation for CDMA *** algorithmiteratively removes detected signals from the received data and searches the residue spatial spectru...
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ISBN:
(纸本)9780780397361
＜正＞In this paper,an iterative high-resolution DOA algorithm is proposed for DOA estimation for CDMA *** algorithmiteratively removes detected signals from the received data and searches the residue spatial spectrum for further *** does not require any computationally expensive eigen decomposition or spatial smoothing in coherent multipath *** are presented illustrating high-resolution at significantly lower SNR levels than those obtained by classical DOA algorithms such as MUSIC and MVM.
In this paper, an iterative high-resolution DOA algorithm is presented for DOA estimation for CDMA systems. The algorithim iteratively removes detected signals from the received data and searches the residue spatial s...
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ISBN:
(纸本)9781424405169
In this paper, an iterative high-resolution DOA algorithm is presented for DOA estimation for CDMA systems. The algorithim iteratively removes detected signals from the received data and searches the residue spatial spectrum for further signals. It does not require any computationally expensive eigen decouiposition or spatial smoothing in coherent multipath scenarios. Results are presented illustrating high-resolution at significantly lower SNR levels than those obtained by classical DOA algorithins such as A4'USIC and MVM.
A class of completely generalized set-valued strongly nonlinear mixed variational-like inequalities is introduced. The auxiliary principle technique is extended to study this new class of mixed variational-like inequa...
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A class of completely generalized set-valued strongly nonlinear mixed variational-like inequalities is introduced. The auxiliary principle technique is extended to study this new class of mixed variational-like inequalities. The existence of a solution of the auxiliary problem for this new class of mixed variational-like inequalities is shown. The iterative algorithm for this new class of mixed variational-like inequalities is given by virtue of this existence result. Moreover, the existence of a solution of this new class of mixed variational-like inequalities and the strong convergence of iterative sequences generated by the algorithm are shown. The convergence criteria are different from some early and recent ones presented in the literature. (c) 2005 Elsevier Ltd. All rights reserved.
We introduce and study a system of variational inclusions involving H-accretive operators in Banach spaces. By using the resolvent operator technique associated with an H-accretive operator, we prove the existence and...
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We introduce and study a system of variational inclusions involving H-accretive operators in Banach spaces. By using the resolvent operator technique associated with an H-accretive operator, we prove the existence and uniqueness of solution for the system of variational inclusions involving H-accretive operators and construct a new iterative algorithm to approximate the unique solution.
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