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Segmentation of region of interest has a critical task in image processing applications. The accuracy of Segmentation is based on processing methodology and limiting value used. In this paper, an enhanced approach of region segmentation using level set (LS) method is proposed, which is achieved by using cross over point in the valley point as a new dynamic stopping criterion in the level set segmentation. The proposed method has been tested with developed database of MR Images. From the test results, it is found that proposed method improves the convergence performance such as complexity in terms of number of iterations, delay and resource overhead as compared to conventional level set based segmentation approach.

Orthogonal frequency division multiplexing (OFDM) has been a crucial problem a high peak to average power ratio (PAPR). In all PAPR reduction scheme, Tone reservation (TR) technology is considered as one of the most promising methods, because of no additional distortion, no side information, and low implementation cost. However, in all PAPR reduction schemes, much iteration is need which have a high computer complexity. In this letter, A novel effective tone reservation method is proposed to reduce the PAPR, which based on the fast convergence adaptive least squares approximation (FCALSA-TR) algorithm can get the optimal peak-canceling signals with less iterations, Simulation results show that the proposed algorithm can achieve almost the same PAPR reduction as that of the clipping control method and just need few iterations.

The power flow in electrical system permits analyzing and studying the steady-state behavior of any grid. Additionally, the power flow helps with the proper planning and management of the system. Therefore, it is increasingly necessary to propose power flows with fast convergence and high efficiency in their results. For this reason, this paper presents an alternative power flow approach for direct current networks with constant power loads based on a truncated Taylor-based approximation. This approach is based on a first-order linear approximation reformulated as a recursive, iterative method. It works with a slope variable concept based on derivatives, which allow few iterations and low processing times. Numerical simulations permit identifying the best power flow approaches reported in the specialized literature for radial and mesh dc grids, including the proposed approach. All the simulations were conducted in MATLAB 2015a. © Published under licence by IOP Publishing Ltd. Universidad Tecnológica de Pereira, UTP: C2018P020 Department of Science, Information Technology and Innovation, Queensland Government, DSITI: Colciencias This work was supported in part by the Administrative Department of Science, Technology and Innovation of Colombia (Colciencias) through the National Scholarship Program under Grant 727-2015 and in part by the Universidad Tecnológica de Bolívar under Project C2018P020.

An emergency braking controller is developed with improved operation characteristics near the maximum friction zone. The methodology is based on self-seeking a-priori unknown optimum operation point to maximize a performance function representing the optimal behavior of the considered dynamic system. Sliding mode with uncertain direction of control vector approach is utilized in the algorithm. An adaptive variable gain is utilized in the algorithm to improve its performance. Via the variable gain, both fast convergence to the a-priori unknown optimum operation point and reduced magnitude of oscillations in the braking moment inputs resulting less aggressive control action are achieved. The author is grateful for the support of the Turkish National Research Council TUBITAK under project no. 112E267 Publisher's Version

In recent years, Bluetooth low energy (BLE) has become a very popular standard for short range wireless communications. The simplified link control layer and concise packet structure make it very appealing to low power applications with medium data rate requirement. However, the very short preamble of a BLE packet is also present as a new design challenge. In such a burst data communication scenario, a short preamble means that only a very short time interval is allowed to adjust the gain of the receiver analog front end to condition the input signal strength to a proper level for decent demodulation in the digital baseband. Aiming at this problem, a fast convergence two-stage automatic gain control (AGC) loop is proposed in this paper. The algorithm is explained in details, and the performance is verified via simulation.

It is well known that based on the structure of a transversal filter, the RLS equaliser provides the fastest convergence in stationary environments. This paper addresses an adaptive transversal equaliser which has the potential to provide more faster convergence than the RLS equaliser. A comparison is made with respect to computational complexity required for each update of equaliser coefficients, and computer simulations are demonstrated to show the superiority of the proposed equaliser., copyright(c)2001 IEICE許諾番号：07RB0174

This paper proposes an acceleration method of GA search that finds a new elite by fitting a single-peak function on GA search surface. The roughest approximation of a finite searching surface that has one global optimum would be a single-peak curved surface, and the vertex of the approximated single-peak function is expected to be near the global optimum of the original searching surface. We propose two data selection methods for the fitting, use a quadratic function as the single-peak function, and evaluate the proposed idea using seven benchmark functions. The experimental results have shown that the proposed method accelerates GA convergence.

This paper present the implementation of a new ordering strategy on Successive Overrelaxation scheme on two dimensional boundary value problems. The strategy involve two directions alternatingly; from top and bottom of the solution domain. The method shows to significantly reduce the iteration number to converge. Four numerical experiments were carried out to examine the performance of the new strategy., {"references":["J. Andres, G. Gabor, and L. Gorniewicz, \"Boundary Value Problems on Infinite Intervals,\" Transactions of The American Mathematical Society, vol. 351, no. 12, pp. 4861-4903, August 1999.","D. M. Young, Iterative Methods for Solving Partial Difference Equations of Elliptic Type, Ph. D. Thesis, Harvard University Cambridge. Massachusets (unpublished).","M. Othman, Implementation of Parallel and Sequential Algorithms for Solving Linear System Iteratively on Shared Memory Multiprocessors Computer System, Ph. D. Thesis, Universiti Kebangsaan Malaysia, Bangi (unpublished).","J. Sulaiman, M. Othman, and M. K. Hasan, \"Red-Black EDG-SOR Iterative Method using Triangle Finite Element Approximation for 2D Poisson Equations,\" in 2007 Computational Science and Its Applications, LNCS 4707, Part III, pp. 298-308.","Y. H. Ng, and M. K. Hasan, \"Investigation of Steady State Problems via Quarter Sweep Schemes,\" Sains Malaysiana, vol. 42, no. 6, pp. 837-844, June 2013.","Y. H. Ng, and M. K. Hasan, \"Steady State Simulator using Alternate Left Right Approach,\" in 2013 AIP Conf. Proceedings of 20th National Symposium on Mathematical Sciences, AIP Conf. Proc. 1522, pp. 757-761."]}

Three-dimensional Laplace problems with a boundary straight-edge singularity caused by two intersecting flat planes are considered. The solution in the neighbourhood of the straight edge can be expressed as an asymptotic expansion involving the eigenpairs of the analogous two-dimensional problem in polar coordinates, which have as coefficients the so-called edge flux intensity functions (EFIFs). The EFIFs are functions of the axial coordinate, the higher derivatives of which appear in an inner infinite series in the expansion. The objective of this work is to extend the singular function boundary integral method (SFBIM), developed for two-dimensional elliptic problems with point boundary singularities [G.C. Georgiou, L. Olson, G. Smyrlis, A singular function boundary integral method for the Laplace equation, Commun. Numer. Methods Eng. 12 (1996) 127-134] for solving the above problem and directly extracting the EFIFs. Approximating the latter by either piecewise constant or linear polynomials eliminates the inner infinite series in the local expansion and allows the straightforward extension of the SFBIM. As in the case of two-dimensional problems, the solution is approximated by the leading terms of the local asymptotic solution expansion. These terms are also used to weight the governing harmonic equation in the Galerkin sense. The resulting discretized equations are reduced to boundary integrals by means of the divergence theorem. The Dirichlet boundary conditions are then weakly enforced by means of Lagrange multipliers. The values of the latter are calculated together with the coefficients of the EFIFs. The SFBIM is applied to a test problem exhibiting fast convergence of order k + 1 (k being the order of the approximation of the EFIFs) in the L 2-norm and leading to accurate estimates for the EFIFs. © 2012 Elsevier Inc. All rights reserved. 219 3 1073 1081 Cited By :2

The problem of characterizing those locally convex spaces satisfying the Mackey convergence condition is still open. Recently in [4], a partial description was given using compatible webs. In this paper, those results are extended by using quasi-sequentially webbed spaces (see Definition 1). In particular, it is shown that strictly barrelled spaces satisfy the Mackey convergence condition and that they are properly contained in the set of quasi-sequentially webbed spaces. A related problem is that of characterizing those locally convex spaces satisfying the so-called fast convergence condition. A partial solution to this problem is obtained. Several examples are given.

Date of Conference: 11-16 Nov. 2007 Conference name: The Second European Conference on Antennas and Propagation, EuCAP 2007 We consider effective preconditioning schemes for the iterative solution of integral-equation methods. For parallel implementations, the sparse approximate inverse or the iterative solution of the near-field system enables fast convergence up to certain problem sizes. However, for very large problems, the near-field matrix itself becomes too crude approximation to the dense system matrix and preconditioners generated from the near-field interactions cannot be effective. Therefore, we propose an approximation strategy to the multilevel fast multipole algorithm (MLFMA) to be used as a preconditioner. Our numerical experiments reveal that this scheme significantly outperforms other preconditioners. With the combined effort of effective preconditioners and an efficiently parallelized MLFMA, we are able to solve targets with tens of millions of unknowns in a few hours.