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101.
This paper proposes a multiple region quantizer composed of quantizers defined on different disjunctive regions of an input signal. In particular, for the two region and the three region cases, the paper provides a complete optimization of a multiple region companded quantizer for the Laplacian source of unit variance. The analysis of the multiple region quantizer is limited to a three region case due to the complexity of the optimization problem and due to the fact that much more complex multiple region quantizer models obtained for a higher number of regions could slightly improve the performances. Two-stage optimization is performed with respect to the number of reconstruction levels of each quantizer composing the considered multiple region companded quantizer and with respect to the region bounds. It is shown that optimal parameters depend only on the fractional part of the required average bit rate. In order to design the three region optimal quantizer, Lloyd–Max's algorithm and Newton–Kantorovich iterative method are used with the three region optimal companded quantizer as the initial solution. The gradient Newton–Kantorovich iterative method is used to provide better convergence speed than Lloyd–Max's algorithm, which is essential in cases where effective initialization solution of Lloyd–Max's algorithm is missing. It is shown that the three region optimal companded quantizer have signal to quantization noise ratio value close to the one of the three region optimal quantizer, where a simpler design procedure is the benefit of the three region optimal companded quantizer over the three region optimal one. 相似文献
102.
《国际计算机数学杂志》2012,89(1):119-137
In this paper we use a new splitting of the matrix A of the linear system A x = b introduced in [1] and we present a new version of the AOR method, more suitable for parallel processing, which involves explicit evaluation of 2 × 2 blocks. We also obtain several convergence conditions for this new method, when the matrix A of (1.1) belongs to different classes of matrices. Some results, given in [1], are also improved and generalised. 相似文献
103.
《国际计算机数学杂志》2012,89(16):2274-2279
In this paper, we introduce a one-step iterative scheme for finding a common fixed point of a countable family of multivalued quasi-nonexpansive mappings in a real uniformly convex Banach space. We establish weak and strong convergence theorems of the proposed iterative scheme under some control conditions. 相似文献
104.
《国际计算机数学杂志》2012,89(3-4):329-335
A method of order three for finding multiple zeros of nonlinear functions is developed. The method requires two evaluations of the function and one evaluation of the derivative per step. 相似文献
105.
《国际计算机数学杂志》2012,89(11):2331-2347
We describe a fast, reliable and automatic algorithm for image sequence inpainting that combines spatio-temporal interpolation with fine texture preservation inside missing areas. The algorithm provides an estimate of the inpainting error by using an automatic geometric recognition of missing regions. Computational kernels are sparse linear systems solved using Generalized Minimum RESidual iterative method equipped with AMG multigrid preconditioner. Experiments on synthetic and real data are discussed. 相似文献
106.
《国际计算机数学杂志》2012,89(4):849-854
In this paper, we present and analyse a new predictor-corrector iterative method for solving non-linear single variable equations. The convergence analysis establishes that the new method is cubically convergent. Numerical tests show that the method is comparable with the well-known existing methods and in many cases gives better results. 相似文献
107.
Jong In Park Norman Kim Suk Joo Bae 《Quality and Reliability Engineering International》2012,28(8):897-909
Accurate prediction of fatigue failure times of materials such as fracture and plastic deformation at various stress ranges has a strong bearing on practical fatigue design of materials. In this study, we propose a novel genetic‐based iterative quantile regression (GA‐IQR) algorithm for analyzing fatigue curves that represent a nonlinear relationship between a given stress amplitude and fatigue life. We reduce the problem to a linear framework and develop the iterative algorithm for determining the model coefficients including unknown fatigue limits. The procedure keeps updating the estimates in a direction to reduce its resulting error. Also, our approach benefits from the population‐based stochastic search of the genetic algorithms so that the algorithm becomes less sensitive to its initialization. Compared with conventional approaches, the proposed GA‐IQR requires fewer assumptions to develop fatigue model, capable of exploring the data structure in a relatively flexible manner. All procedures and calculations are quite straightforward, such that the proposed quantile regression model has a high potential value in a wide range of applications for exploring nonlinear relationships with lifetime data. Computational results for real data sets found in the literature present good evidences to support the argument. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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